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Eric W. Biederman 4c376dcae8 userns: Convert struct dquot dq_id to be a struct kqid
Change struct dquot dq_id to a struct kqid and remove the now
unecessary dq_type.

Make minimal changes to dquot, quota_tree, quota_v1, quota_v2, ext3,
ext4, and ocfs2 to deal with the change in quota structures and
signatures.  The ocfs2 changes are larger than most because of the
extensive tracing throughout the ocfs2 quota code that prints out
dq_id.

quota_tree.c:get_index is modified to take a struct kqid instead of a
qid_t because all of it's callers pass in dquot->dq_id and it allows
me to introduce only a single conversion.

The rest of the changes are either just replacing dq_type with dq_id.type,
adding conversions to deal with the change in type and occassionally
adding qid_eq to allow quota id comparisons in a user namespace safe way.

Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Theodore Tso <tytso@mit.edu>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-18 01:01:41 -07:00
Eric W. Biederman aca645a6a5 userns: Modify dqget to take struct kqid
Modify dqget to take struct kqid instead of a type and an identifier
pair.

Modify the callers of dqget in ocfs2 and dquot to take generate
a struct kqid so they can continue to call dqget.  The conversion
to create struct kqid should all be the final conversions that
are needed in those code paths.

Cc: Jan Kara <jack@suse.cz>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-18 01:01:40 -07:00
Eric W. Biederman 431f19744d userns: Convert quota netlink aka quota_send_warning
Modify quota_send_warning to take struct kqid instead a type and
identifier pair.

When sending netlink broadcasts always convert uids and quota
identifiers into the intial user namespace.  There is as yet no way to
send a netlink broadcast message with different contents to receivers
in different namespaces, so for the time being just map all of the
identifiers into the initial user namespace which preserves the
current behavior.

Change the callers of quota_send_warning in gfs2, xfs and dquot
to generate a struct kqid to pass to quota send warning.  When
all of the user namespaces convesions are complete a struct kqid
values will be availbe without need for conversion, but a conversion
is needed now to avoid needing to convert everything at once.

Cc: Ben Myers <bpm@sgi.com>
Cc: Alex Elder <elder@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-18 01:01:40 -07:00
Eric W. Biederman 74a8a10378 userns: Convert qutoactl
Update the quotactl user space interface to successfull compile with
user namespaces support enabled and to hand off quota identifiers to
lower layers of the kernel in struct kqid instead of type and qid
pairs.

The quota on function is not converted because while it takes a quota
type and an id.  The id is the on disk quota format to use, which
is something completely different.

The signature of two struct quotactl_ops methods were changed to take
struct kqid argumetns get_dqblk and set_dqblk.

The dquot, xfs, and ocfs2 implementations of get_dqblk and set_dqblk
are minimally changed so that the code continues to work with
the change in parameter type.

This is the first in a series of changes to always store quota
identifiers in the kernel in struct kqid and only use raw type and qid
values when interacting with on disk structures or userspace.  Always
using struct kqid internally makes it hard to miss places that need
conversion to or from the kernel internal values.

Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Ben Myers <bpm@sgi.com>
Cc: Alex Elder <elder@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-18 01:01:39 -07:00
Eric W. Biederman e8a3e4719b userns: Implement struct kqid
Add the data type struct kqid which holds the kernel internal form of
the owning identifier of a quota.  struct kqid is a replacement for
the implicit union of uid, gid and project id stored in an unsigned
int and the quota type field that is was used in the quota data
structures.  Making the data type explicit allows the kuid_t and
kgid_t type safety to propogate more thoroughly through the code,
revealing more places where uid/gid conversions need be made.

Along with the data type struct kqid comes the helper functions
qid_eq, qid_lt, from_kqid, from_kqid_munged, qid_valid, make_kqid,
make_kqid_invalid, make_kqid_uid, make_kqid_gid.

Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-18 01:01:38 -07:00
Eric W. Biederman f76d207a66 userns: Add kprojid_t and associated infrastructure in projid.h
Implement kprojid_t a cousin of the kuid_t and kgid_t.

The per user namespace mapping of project id values can be set with
/proc/<pid>/projid_map.

A full compliment of helpers is provided: make_kprojid, from_kprojid,
from_kprojid_munged, kporjid_has_mapping, projid_valid, projid_eq,
projid_eq, projid_lt.

Project identifiers are part of the generic disk quota interface,
although it appears only xfs implements project identifiers currently.

The xfs code allows anyone who has permission to set the project
identifier on a file to use any project identifier so when
setting up the user namespace project identifier mappings I do
not require a capability.

Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-18 01:01:37 -07:00
Eric W. Biederman 5f3a4a28ec userns: Pass a userns parameter into posix_acl_to_xattr and posix_acl_from_xattr
- Pass the user namespace the uid and gid values in the xattr are stored
   in into posix_acl_from_xattr.

 - Pass the user namespace kuid and kgid values should be converted into
   when storing uid and gid values in an xattr in posix_acl_to_xattr.

- Modify all callers of posix_acl_from_xattr and posix_acl_to_xattr to
  pass in &init_user_ns.

In the short term this change is not strictly needed but it makes the
code clearer.  In the longer term this change is necessary to be able to
mount filesystems outside of the initial user namespace that natively
store posix acls in the linux xattr format.

Cc: Theodore Tso <tytso@mit.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-18 01:01:35 -07:00
Eric W. Biederman 2f6f0654ab userns: Convert vfs posix_acl support to use kuids and kgids
- In setxattr if we are setting a posix acl convert uids and gids from
  the current user namespace into the initial user namespace, before
  the xattrs are passed to the underlying filesystem.

  Untranslatable uids and gids are represented as -1 which
  posix_acl_from_xattr will represent as INVALID_UID or INVALID_GID.
  posix_acl_valid will fail if an acl from userspace has any
  INVALID_UID or INVALID_GID values.  In net this guarantees that
  untranslatable posix acls will not be stored by filesystems.

- In getxattr if we are reading a posix acl convert uids and gids from
  the initial user namespace into the current user namespace.

  Uids and gids that can not be tranlsated into the current user namespace
  will be represented as -1.

- Replace e_id in struct posix_acl_entry with an anymouns union of
  e_uid and e_gid.  For the short term retain the e_id field
  until all of the users are converted.

- Don't set struct posix_acl.e_id in the cases where the acl type
  does not use e_id.  Greatly reducing the use of ACL_UNDEFINED_ID.

- Rework the ordering checks in posix_acl_valid so that I use kuid_t
  and kgid_t types throughout the code, and so that I don't need
  arithmetic on uid and gid types.

Cc: Theodore Tso <tytso@mit.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-18 01:01:35 -07:00
Eric W. Biederman 4bd6e32ace userns: Convert taskstats to handle the user and pid namespaces.
- Explicitly limit exit task stat broadcast to the initial user and
  pid namespaces, as it is already limited to the initial network
  namespace.

- For broadcast task stats explicitly generate all of the idenitiers
  in terms of the initial user namespace and the initial pid
  namespace.

- For request stats report them in terms of the current user namespace
  and the current pid namespace.  Netlink messages are delivered
  syncrhonously to the kernel allowing us to get the user namespace
  and the pid namespace from the current task.

- Pass the namespaces for representing pids and uids and gids
  into bacct_add_task.

Cc: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-18 01:01:32 -07:00
Eric W. Biederman e1760bd5ff userns: Convert the audit loginuid to be a kuid
Always store audit loginuids in type kuid_t.

Print loginuids by converting them into uids in the appropriate user
namespace, and then printing the resulting uid.

Modify audit_get_loginuid to return a kuid_t.

Modify audit_set_loginuid to take a kuid_t.

Modify /proc/<pid>/loginuid on read to convert the loginuid into the
user namespace of the opener of the file.

Modify /proc/<pid>/loginud on write to convert the loginuid
rom the user namespace of the opener of the file.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Paul Moore <paul@paul-moore.com> ?
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-17 18:08:54 -07:00
Eric W. Biederman ca57ec0f00 audit: Add typespecific uid and gid comparators
The audit filter code guarantees that uid are always compared with
uids and gids are always compared with gids, as the comparason
operations are type specific.  Take advantage of this proper to define
audit_uid_comparator and audit_gid_comparator which use the type safe
comparasons from uidgid.h.

Build on audit_uid_comparator and audit_gid_comparator and replace
audit_compare_id with audit_compare_uid and audit_compare_gid.  This
is one of those odd cases where being type safe and duplicating code
leads to simpler shorter and more concise code.

Don't allow bitmask operations in uid and gid comparisons in
audit_data_to_entry.  Bitmask operations are already denined in
audit_rule_to_entry.

Convert constants in audit_rule_to_entry and audit_data_to_entry into
kuids and kgids when appropriate.

Convert the uid and gid field in struct audit_names to be of type
kuid_t and kgid_t respectively, so that the new uid and gid comparators
can be applied in a type safe manner.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-17 18:08:09 -07:00
Eric W. Biederman 017143fecb audit: Remove the unused uid parameter from audit_receive_filter
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-17 18:07:07 -07:00
Eric W. Biederman 02276bda4a audit: Use current instead of NETLINK_CREDS() in audit_filter
Get caller process uid and gid and pid values from the current task
instead of the NETLINK_CB.  This is simpler than passing NETLINK_CREDS
from from audit_receive_msg to audit_filter_user_rules and avoid the
chance of being hit by the occassional bugs in netlink uid/gid
credential passing.  This is a safe changes because all netlink
requests are processed in the task of the sending process.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-17 18:03:31 -07:00
Eric W. Biederman 9a56c2db49 userns: Convert security/keys to the new userns infrastructure
- Replace key_user ->user_ns equality checks with kuid_has_mapping checks.
- Use from_kuid to generate key descriptions
- Use kuid_t and kgid_t and the associated helpers instead of uid_t and gid_t
- Avoid potential problems with file descriptor passing by displaying
  keys in the user namespace of the opener of key status proc files.

Cc: linux-security-module@vger.kernel.org
Cc: keyrings@linux-nfs.org
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-13 18:28:02 -07:00
Eric W. Biederman 1efdb69b0b userns: Convert ipc to use kuid and kgid where appropriate
- Store the ipc owner and creator with a kuid
- Store the ipc group and the crators group with a kgid.
- Add error handling to ipc_update_perms, allowing it to
  fail if the uids and gids can not be converted to kuids
  or kgids.
- Modify the proc files to display the ipc creator and
  owner in the user namespace of the opener of the proc file.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-06 22:17:20 -07:00
Eric W. Biederman d06ca95643 userns: Teach inet_diag to work with user namespaces
Compute the user namespace of the socket that we are replying to
and translate the kuids of reported sockets into that user namespace.

Cc: Andrew Vagin <avagin@openvz.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-08-14 21:55:20 -07:00
Eric W. Biederman 3fbc290540 netlink: Make the sending netlink socket availabe in NETLINK_CB
The sending socket of an skb is already available by it's port id
in the NETLINK_CB.  If you want to know more like to examine the
credentials on the sending socket you have to look up the sending
socket by it's port id and all of the needed functions and data
structures are static inside of af_netlink.c.  So do the simple
thing and pass the sending socket to the receivers in the NETLINK_CB.

I intend to use this to get the user namespace of the sending socket
in inet_diag so that I can report uids in the context of the process
who opened the socket, the same way I report uids in the contect
of the process who opens files.

Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-08-14 21:49:49 -07:00
Eric W. Biederman adb37c4c67 userns: Make seq_file's user namespace accessible
struct file already has a user namespace associated with it
in file->f_cred->user_ns, unfortunately because struct
seq_file has no struct file backpointer associated with
it, it is difficult to get at the user namespace in seq_file
context.  Therefore add a helper function seq_user_ns to return
the associated user namespace and a user_ns field to struct
seq_file to be used in implementing seq_user_ns.

Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-08-14 21:47:55 -07:00
Linus Torvalds fc6bdb59a5 Merge branch 'for-linus-3.6' of git://dev.laptop.org/users/dilinger/linux-olpc
Pull OLPC platform updates from Andres Salomon:
 "These move the OLPC Embedded Controller driver out of
  arch/x86/platform and into drivers/platform/olpc.

  OLPC machines are now ARM-based (which means lots of x86 and ARM
  changes), but are typically pretty self-contained..  so it makes more
  sense to go through a separate OLPC tree after getting the appropriate
  review/ACKs."

* 'for-linus-3.6' of git://dev.laptop.org/users/dilinger/linux-olpc:
  x86: OLPC: move s/r-related EC cmds to EC driver
  Platform: OLPC: move global variables into priv struct
  Platform: OLPC: move debugfs support from x86 EC driver
  x86: OLPC: switch over to using new EC driver on x86
  Platform: OLPC: add a suspended flag to the EC driver
  Platform: OLPC: turn EC driver into a platform_driver
  Platform: OLPC: allow EC cmd to be overridden, and create a workqueue to call it
  drivers: OLPC: update various drivers to include olpc-ec.h
  Platform: OLPC: add a stub to drivers/platform/ for the OLPC EC driver
2012-08-02 11:52:39 -07:00
Linus Torvalds 0a276d1675 SuperH fixes for 3.6-rc1 merge window
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Merge tag 'sh-for-linus' of git://github.com/pmundt/linux-sh

Pull SuperH fixes from Paul Mundt.

* tag 'sh-for-linus' of git://github.com/pmundt/linux-sh: (24 commits)
  sh: explicitly include sh_dma.h in setup-sh7722.c
  sh: ecovec: care CN5 VBUS if USB host mode
  sh: sh7724: fixup renesas_usbhs clock settings
  sh: intc: initial irqdomain support.
  sh: pfc: Fix up init ordering mess.
  serial: sh-sci: fix compilation breakage, when DMA is enabled
  dmaengine: shdma: restore partial transfer calculation
  sh: modify the sh_dmae_slave_config for RSPI in setup-sh7757
  sh: Fix up recursive fault in oops with unset TTB.
  sh: pfc: Build fix for pinctrl_remove_gpio_range() changes.
  sh: select the fixed regulator driver on several boards
  sh: ecovec: switch MMC power control to regulators
  sh: add fixed voltage regulators to se7724
  sh: add fixed voltage regulators to sdk7786
  sh: add fixed voltage regulators to rsk
  sh: add fixed voltage regulators to migor
  sh: add fixed voltage regulators to kfr2r09
  sh: add fixed voltage regulators to ap325rxa
  sh: add fixed voltage regulators to sh7757lcr
  sh: add fixed voltage regulators to sh2007
  ...
2012-08-02 11:45:42 -07:00
Linus Torvalds a6dc77254b Merge branch 'dmaengine' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM DMA engine updates from Russell King:
 "This looks scary at first glance, but what it is is:
   - a rework of the sa11x0 DMA engine driver merged during the previous
     cycle, to extract a common set of helper functions for DMA engine
     implementations.
   - conversion of amba-pl08x.c to use these helper functions.
   - addition of OMAP DMA engine driver (using these helper functions),
     and conversion of some of the OMAP DMA users to use DMA engine.

  Nothing in the helper functions is ARM specific, so I hope that other
  implementations can consolidate some of their code by making use of
  these helpers.

  This has been sitting in linux-next most of the merge cycle, and has
  been tested by several OMAP folk.  I've tested it on sa11x0 platforms,
  and given it my best shot on my broken platforms which have the
  amba-pl08x controller.

  The last point is the addition to feature-removal-schedule.txt, which
  will have a merge conflict.  Between myself and TI, we're planning to
  remove the old TI DMA implementation next year."

Fix up trivial add/add conflicts in Documentation/feature-removal-schedule.txt
and drivers/dma/{Kconfig,Makefile}

* 'dmaengine' of git://git.linaro.org/people/rmk/linux-arm: (53 commits)
  ARM: 7481/1: OMAP2+: omap2plus_defconfig: enable OMAP DMA engine
  ARM: 7464/1: mmc: omap_hsmmc: ensure probe returns error if DMA channel request fails
  Add feature removal of old OMAP private DMA implementation
  mtd: omap2: remove private DMA API implementation
  mtd: omap2: add DMA engine support
  spi: omap2-mcspi: remove private DMA API implementation
  spi: omap2-mcspi: add DMA engine support
  ARM: omap: remove mmc platform data dma_mask and initialization
  mmc: omap: remove private DMA API implementation
  mmc: omap: add DMA engine support
  mmc: omap_hsmmc: remove private DMA API implementation
  mmc: omap_hsmmc: add DMA engine support
  dmaengine: omap: add support for cyclic DMA
  dmaengine: omap: add support for setting fi
  dmaengine: omap: add support for returning residue in tx_state method
  dmaengine: add OMAP DMA engine driver
  dmaengine: sa11x0-dma: add cyclic DMA support
  dmaengine: sa11x0-dma: fix DMA residue support
  dmaengine: PL08x: ensure all descriptors are freed when channel is released
  dmaengine: PL08x: get rid of write only pool_ctr and free_txd locking
  ...
2012-08-01 16:41:07 -07:00
Linus Torvalds a0e881b7c1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull second vfs pile from Al Viro:
 "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the
  deadlock reproduced by xfstests 068), symlink and hardlink restriction
  patches, plus assorted cleanups and fixes.

  Note that another fsfreeze deadlock (emergency thaw one) is *not*
  dealt with - the series by Fernando conflicts a lot with Jan's, breaks
  userland ABI (FIFREEZE semantics gets changed) and trades the deadlock
  for massive vfsmount leak; this is going to be handled next cycle.
  There probably will be another pull request, but that stuff won't be
  in it."

Fix up trivial conflicts due to unrelated changes next to each other in
drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c}

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits)
  delousing target_core_file a bit
  Documentation: Correct s_umount state for freeze_fs/unfreeze_fs
  fs: Remove old freezing mechanism
  ext2: Implement freezing
  btrfs: Convert to new freezing mechanism
  nilfs2: Convert to new freezing mechanism
  ntfs: Convert to new freezing mechanism
  fuse: Convert to new freezing mechanism
  gfs2: Convert to new freezing mechanism
  ocfs2: Convert to new freezing mechanism
  xfs: Convert to new freezing code
  ext4: Convert to new freezing mechanism
  fs: Protect write paths by sb_start_write - sb_end_write
  fs: Skip atime update on frozen filesystem
  fs: Add freezing handling to mnt_want_write() / mnt_drop_write()
  fs: Improve filesystem freezing handling
  switch the protection of percpu_counter list to spinlock
  nfsd: Push mnt_want_write() outside of i_mutex
  btrfs: Push mnt_want_write() outside of i_mutex
  fat: Push mnt_want_write() outside of i_mutex
  ...
2012-08-01 10:26:23 -07:00
Linus Torvalds eff0d13f38 Merge branch 'for-3.6/drivers' of git://git.kernel.dk/linux-block
Pull block driver changes from Jens Axboe:

 - Making the plugging support for drivers a bit more sane from Neil.
   This supersedes the plugging change from Shaohua as well.

 - The usual round of drbd updates.

 - Using a tail add instead of a head add in the request completion for
   ndb, making us find the most completed request more quickly.

 - A few floppy changes, getting rid of a duplicated flag and also
   running the floppy init async (since it takes forever in boot terms)
   from Andi.

* 'for-3.6/drivers' of git://git.kernel.dk/linux-block:
  floppy: remove duplicated flag FD_RAW_NEED_DISK
  blk: pass from_schedule to non-request unplug functions.
  block: stack unplug
  blk: centralize non-request unplug handling.
  md: remove plug_cnt feature of plugging.
  block/nbd: micro-optimization in nbd request completion
  drbd: announce FLUSH/FUA capability to upper layers
  drbd: fix max_bio_size to be unsigned
  drbd: flush drbd work queue before invalidate/invalidate remote
  drbd: fix potential access after free
  drbd: call local-io-error handler early
  drbd: do not reset rs_pending_cnt too early
  drbd: reset congestion information before reporting it in /proc/drbd
  drbd: report congestion if we are waiting for some userland callback
  drbd: differentiate between normal and forced detach
  drbd: cleanup, remove two unused global flags
  floppy: Run floppy initialization asynchronous
2012-08-01 09:06:47 -07:00
Linus Torvalds 8cf1a3fce0 Merge branch 'for-3.6/core' of git://git.kernel.dk/linux-block
Pull core block IO bits from Jens Axboe:
 "The most complicated part if this is the request allocation rework by
  Tejun, which has been queued up for a long time and has been in
  for-next ditto as well.

  There are a few commits from yesterday and today, mostly trivial and
  obvious fixes.  So I'm pretty confident that it is sound.  It's also
  smaller than usual."

* 'for-3.6/core' of git://git.kernel.dk/linux-block:
  block: remove dead func declaration
  block: add partition resize function to blkpg ioctl
  block: uninitialized ioc->nr_tasks triggers WARN_ON
  block: do not artificially constrain max_sectors for stacking drivers
  blkcg: implement per-blkg request allocation
  block: prepare for multiple request_lists
  block: add q->nr_rqs[] and move q->rq.elvpriv to q->nr_rqs_elvpriv
  blkcg: inline bio_blkcg() and friends
  block: allocate io_context upfront
  block: refactor get_request[_wait]()
  block: drop custom queue draining used by scsi_transport_{iscsi|fc}
  mempool: add @gfp_mask to mempool_create_node()
  blkcg: make root blkcg allocation use %GFP_KERNEL
  blkcg: __blkg_lookup_create() doesn't need radix preload
2012-08-01 09:02:41 -07:00
J. Bruce Fields 068535f1fe locks: remove unused lm_release_private
In commit 3b6e2723f3 ("locks: prevent side-effects of
locks_release_private before file_lock is initialized") we removed the
last user of lm_release_private without removing the field itself.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01 09:01:46 -07:00
Vivek Goyal c83f6bf98d block: add partition resize function to blkpg ioctl
Add a new operation code (BLKPG_RESIZE_PARTITION) to the BLKPG ioctl that
allows altering the size of an existing partition, even if it is currently
in use.

This patch converts hd_struct->nr_sects into sequence counter because
One might extend a partition while IO is happening to it and update of
nr_sects can be non-atomic on 32bit machines with 64bit sector_t. This
can lead to issues like reading inconsistent size of a partition. Sequence
counter have been used so that readers don't have to take bdev mutex lock
as we call sector_in_part() very frequently.

Now all the access to hd_struct->nr_sects should happen using sequence
counter read/update helper functions part_nr_sects_read/part_nr_sects_write.
There is one exception though, set_capacity()/get_capacity(). I think
theoritically race should exist there too but this patch does not
modify set_capacity()/get_capacity() due to sheer number of call sites
and I am afraid that change might break something. I have left that as a
TODO item. We can handle it later if need be. This patch does not introduce
any new races as such w.r.t set_capacity()/get_capacity().

v2: Add CONFIG_LBDAF test to UP preempt case as suggested by Phillip.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Phillip Susi <psusi@ubuntu.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-08-01 12:24:18 +02:00
Paul Mundt f38770477a Merge branch 'common/irqdomain' into sh-latest 2012-08-01 17:14:52 +09:00
Guennadi Liakhovetski 4f46f8ac80 dmaengine: shdma: restore partial transfer calculation
The recent shdma driver split has mistakenly removed support for partial
DMA transfer size calculation on forced termination. This patch restores
it.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Vinod Koul <vinod.koul@linux.intel.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2012-08-01 13:48:52 +09:00
Linus Torvalds 2d53492620 irqdomain changes for Linux v3.6
Round of refactoring and enhancements to irq_domain infrastructure. This
 series starts the process of simplifying irqdomain. The ultimate goal is
 to merge LEGACY, LINEAR and TREE mappings into a single system, but had
 to back off from that after some last minute bugs. Instead it mainly
 reorganizes the code and ensures that the reverse map gets populated
 when the irq is mapped instead of the first time it is looked up.
 
 Merging of the irq_domain types is deferred to v3.7
 
 In other news, this series adds helpers for creating static mappings on
 a linear or tree mapping.
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Merge tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux-2.6

Pull irqdomain changes from Grant Likely:
 "Round of refactoring and enhancements to irq_domain infrastructure.
  This series starts the process of simplifying irqdomain.  The ultimate
  goal is to merge LEGACY, LINEAR and TREE mappings into a single
  system, but had to back off from that after some last minute bugs.
  Instead it mainly reorganizes the code and ensures that the reverse
  map gets populated when the irq is mapped instead of the first time it
  is looked up.

  Merging of the irq_domain types is deferred to v3.7

  In other news, this series adds helpers for creating static mappings
  on a linear or tree mapping."

* tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux-2.6:
  irqdomain: Improve diagnostics when a domain mapping fails
  irqdomain: eliminate slow-path revmap lookups
  irqdomain: Fix irq_create_direct_mapping() to test irq_domain type.
  irqdomain: Eliminate dedicated radix lookup functions
  irqdomain: Support for static IRQ mapping and association.
  irqdomain: Always update revmap when setting up a virq
  irqdomain: Split disassociating code into separate function
  irq_domain: correct a minor wrong comment for linear revmap
  irq_domain: Standardise legacy/linear domain selection
  irqdomain: Make ops->map hook optional
  irqdomain: Remove unnecessary test for IRQ_DOMAIN_MAP_LEGACY
  irqdomain: Simple NUMA awareness.
  devicetree: add helper inline for retrieving a node's full name
2012-07-31 20:44:03 -07:00
Andres Salomon ac2504151f Platform: OLPC: turn EC driver into a platform_driver
The 1.75-based OLPC EC driver already does this; let's do it for all EC
drivers.  This gives us nice suspend/resume hooks, amongst other things.

We want to run the EC's suspend hooks later than other drivers (which may
be setting wakeup masks or be running EC commands).  We also want to run
the EC's resume hooks earlier than other drivers (which may want to run EC
commands).

Signed-off-by: Andres Salomon <dilinger@queued.net>
Acked-by: Paul Fox <pgf@laptop.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-31 23:27:30 -04:00
Andres Salomon 3d26c20bae Platform: OLPC: allow EC cmd to be overridden, and create a workqueue to call it
This provides a new API allows different OLPC architectures to override the
EC driver.  x86 and ARM OLPC machines use completely different EC backends.

The olpc_ec_cmd is synchronous, and waits for the workqueue to send the
command to the EC.  Multiple callers can run olpc_ec_cmd() at once, and
they will by serialized and sleep while only one executes on the EC at a time.

We don't provide an unregister function, as that doesn't make sense within
the context of OLPC machines - there's only ever 1 EC, it's critical to
functionality, and it certainly not hotpluggable.

Signed-off-by: Andres Salomon <dilinger@queued.net>
Acked-by: Paul Fox <pgf@laptop.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-31 23:27:30 -04:00
Andres Salomon 392a325c43 Platform: OLPC: add a stub to drivers/platform/ for the OLPC EC driver
The OLPC EC driver has outgrown arch/x86/platform/.  It's time to both
share common code amongst different architectures, as well as move it out
of arch/x86/.  The XO-1.75 is ARM-based, and the EC driver shares a lot of
code with the x86 code.

Signed-off-by: Andres Salomon <dilinger@queued.net>
Acked-by: Paul Fox <pgf@laptop.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2012-07-31 23:27:29 -04:00
Linus Torvalds ac694dbdbc Merge branch 'akpm' (Andrew's patch-bomb)
Merge Andrew's second set of patches:
 - MM
 - a few random fixes
 - a couple of RTC leftovers

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (120 commits)
  rtc/rtc-88pm80x: remove unneed devm_kfree
  rtc/rtc-88pm80x: assign ret only when rtc_register_driver fails
  mm: hugetlbfs: close race during teardown of hugetlbfs shared page tables
  tmpfs: distribute interleave better across nodes
  mm: remove redundant initialization
  mm: warn if pg_data_t isn't initialized with zero
  mips: zero out pg_data_t when it's allocated
  memcg: gix memory accounting scalability in shrink_page_list
  mm/sparse: remove index_init_lock
  mm/sparse: more checks on mem_section number
  mm/sparse: optimize sparse_index_alloc
  memcg: add mem_cgroup_from_css() helper
  memcg: further prevent OOM with too many dirty pages
  memcg: prevent OOM with too many dirty pages
  mm: mmu_notifier: fix freed page still mapped in secondary MMU
  mm: memcg: only check anon swapin page charges for swap cache
  mm: memcg: only check swap cache pages for repeated charging
  mm: memcg: split swapin charge function into private and public part
  mm: memcg: remove needless !mm fixup to init_mm when charging
  mm: memcg: remove unneeded shmem charge type
  ...
2012-07-31 19:25:39 -07:00
Linus Torvalds a40a1d3d0a VFIO for v3.6
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Merge tag 'vfio-for-v3.6' of git://github.com/awilliam/linux-vfio

Pull VFIO core from Alex Williamson:
 "This series includes the VFIO userspace driver interface for the 3.6
  kernel merge window.  This driver is intended to provide a secure
  interface for device access using IOMMU protection for applications
  like assignment of physical devices to virtual machines.

  Qemu will be the first user of this interface, enabling assignment of
  PCI devices to Qemu guests.  This interface is intended to eventually
  replace the x86-specific assignment mechanism currently available in
  KVM.

  This interface has the advantage of being more secure, by working with
  IOMMU groups to ensure device isolation and providing it's own
  filtered resource access mechanism, and also more flexible, in not
  being x86 or KVM specific (extensions to enable POWER are already
  working).

  This driver is originally the work of Tom Lyon, but has since been
  handed over to me and gone through a complete overhaul thanks to the
  input from David Gibson, Ben Herrenschmidt, Chris Wright, Joerg
  Roedel, and others.  This driver has been available in linux-next for
  the last month."

Paul Mackerras says:
 "I would be glad to see it go in since we want to use it with KVM on
  PowerPC.  If possible we'd like the PowerPC bits for it to go in as
  well."

* tag 'vfio-for-v3.6' of git://github.com/awilliam/linux-vfio:
  vfio: Add PCI device driver
  vfio: Type1 IOMMU implementation
  vfio: Add documentation
  vfio: VFIO core
2012-07-31 19:17:27 -07:00
Linus Torvalds 3e9a97082f This patch series contains a major revamp of how we collect entropy
from interrupts for /dev/random and /dev/urandom.  The goal is to
 addresses weaknesses discussed in the paper "Mining your Ps and Qs:
 Detection of Widespread Weak Keys in Network Devices", by Nadia
 Heninger, Zakir Durumeric, Eric Wustrow, J. Alex Halderman, which will
 be published in the Proceedings of the 21st Usenix Security Symposium,
 August 2012.  (See https://factorable.net for more information and an
 extended version of the paper.)
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Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random

Pull random subsystem patches from Ted Ts'o:
 "This patch series contains a major revamp of how we collect entropy
  from interrupts for /dev/random and /dev/urandom.

  The goal is to addresses weaknesses discussed in the paper "Mining
  your Ps and Qs: Detection of Widespread Weak Keys in Network Devices",
  by Nadia Heninger, Zakir Durumeric, Eric Wustrow, J.  Alex Halderman,
  which will be published in the Proceedings of the 21st Usenix Security
  Symposium, August 2012.  (See https://factorable.net for more
  information and an extended version of the paper.)"

Fix up trivial conflicts due to nearby changes in
drivers/{mfd/ab3100-core.c, usb/gadget/omap_udc.c}

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: (33 commits)
  random: mix in architectural randomness in extract_buf()
  dmi: Feed DMI table to /dev/random driver
  random: Add comment to random_initialize()
  random: final removal of IRQF_SAMPLE_RANDOM
  um: remove IRQF_SAMPLE_RANDOM which is now a no-op
  sparc/ldc: remove IRQF_SAMPLE_RANDOM which is now a no-op
  [ARM] pxa: remove IRQF_SAMPLE_RANDOM which is now a no-op
  board-palmz71: remove IRQF_SAMPLE_RANDOM which is now a no-op
  isp1301_omap: remove IRQF_SAMPLE_RANDOM which is now a no-op
  pxa25x_udc: remove IRQF_SAMPLE_RANDOM which is now a no-op
  omap_udc: remove IRQF_SAMPLE_RANDOM which is now a no-op
  goku_udc: remove IRQF_SAMPLE_RANDOM which was commented out
  uartlite: remove IRQF_SAMPLE_RANDOM which is now a no-op
  drivers: hv: remove IRQF_SAMPLE_RANDOM which is now a no-op
  xen-blkfront: remove IRQF_SAMPLE_RANDOM which is now a no-op
  n2_crypto: remove IRQF_SAMPLE_RANDOM which is now a no-op
  pda_power: remove IRQF_SAMPLE_RANDOM which is now a no-op
  i2c-pmcmsp: remove IRQF_SAMPLE_RANDOM which is now a no-op
  input/serio/hp_sdc.c: remove IRQF_SAMPLE_RANDOM which is now a no-op
  mfd: remove IRQF_SAMPLE_RANDOM which is now a no-op
  ...
2012-07-31 19:07:42 -07:00
Linus Torvalds 8762541f06 Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull second set of media updates from Mauro Carvalho Chehab:

 - radio API: add support to work with radio frequency bands

 - new AM/FM radio drivers: radio-shark, radio-shark2

 - new Remote Controller USB driver: iguanair

 - conversion of several drivers to the v4l2 core control framework

 - new board additions at existing drivers

 - the remaining (and vast majority of the patches) are due to
   drivers/DocBook fixes/cleanups.

* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (154 commits)
  [media] radio-tea5777: use library for 64bits div
  [media] tlg2300: Declare MODULE_FIRMWARE usage
  [media] lgs8gxx: Declare MODULE_FIRMWARE usage
  [media] xc5000: Add MODULE_FIRMWARE statements
  [media] s2255drv: Add MODULE_FIRMWARE statement
  [media] dib8000: move dereference after check for NULL
  [media] Documentation: Update cardlists
  [media] bttv: add support for Aposonic W-DVR
  [media] cx25821: Remove bad strcpy to read-only char*
  [media] pms.c: remove duplicated include
  [media] smiapp-core.c: remove duplicated include
  [media] via-camera: pass correct format settings to sensor
  [media] rtl2832.c: minor cleanup
  [media] Add support for the IguanaWorks USB IR Transceiver
  [media] Minor cleanups for MCE USB
  [media] drivers/media/dvb/siano/smscoreapi.c: use list_for_each_entry
  [media] Use a named union in struct v4l2_ioctl_info
  [media] mceusb: Add Twisted Melon USB IDs
  [media] staging/media/solo6x10: use module_pci_driver macro
  [media] staging/media/dt3155v4l: use module_pci_driver macro
  ...

Conflicts:
	Documentation/feature-removal-schedule.txt
2012-07-31 18:47:44 -07:00
Linus Torvalds 6dbb35b0a7 NFS client updates for Linux 3.6
Features include:
 - Patches from Bryan to allow splitting of the NFSv2/v3/v4 code into
   separate modules.
 - Fix Oopses in the NFSv4 idmapper
 - Fix a deadlock whereby rpciod tries to allocate a new socket and
   ends up recursing into the NFS code due to memory reclaim.
 - Increase the number of permitted callback connections.
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Merge tag 'nfs-for-3.6-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull second wave of NFS client updates from Trond Myklebust:

 - Patches from Bryan to allow splitting of the NFSv2/v3/v4 code into
   separate modules.

 - Fix Oopses in the NFSv4 idmapper

 - Fix a deadlock whereby rpciod tries to allocate a new socket and ends
   up recursing into the NFS code due to memory reclaim.

 - Increase the number of permitted callback connections.

* tag 'nfs-for-3.6-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  nfs: explicitly reject LOCK_MAND flock() requests
  nfs: increase number of permitted callback connections.
  SUNRPC: return negative value in case rpcbind client creation error
  NFS: Convert v4 into a module
  NFS: Convert v3 into a module
  NFS: Convert v2 into a module
  NFS: Keep module parameters in the generic NFS client
  NFS: Split out remaining NFS v4 inode functions
  NFS: Pass super operations and xattr handlers in the nfs_subversion
  NFS: Only initialize the ACL client in the v3 case
  NFS: Create a try_mount rpc op
  NFS: Remove the NFS v4 xdev mount function
  NFS: Add version registering framework
  NFS: Fix a number of bugs in the idmapper
  nfs: skip commit in releasepage if we're freeing memory for fs-related reasons
  sunrpc: clarify comments on rpc_make_runnable
  pnfsblock: bail out partial page IO
2012-07-31 18:45:44 -07:00
Mel Gorman d833352a43 mm: hugetlbfs: close race during teardown of hugetlbfs shared page tables
If a process creates a large hugetlbfs mapping that is eligible for page
table sharing and forks heavily with children some of whom fault and
others which destroy the mapping then it is possible for page tables to
get corrupted.  Some teardowns of the mapping encounter a "bad pmd" and
output a message to the kernel log.  The final teardown will trigger a
BUG_ON in mm/filemap.c.

This was reproduced in 3.4 but is known to have existed for a long time
and goes back at least as far as 2.6.37.  It was probably was introduced
in 2.6.20 by [39dde65c: shared page table for hugetlb page].  The messages
look like this;

[  ..........] Lots of bad pmd messages followed by this
[  127.164256] mm/memory.c:391: bad pmd ffff880412e04fe8(80000003de4000e7).
[  127.164257] mm/memory.c:391: bad pmd ffff880412e04ff0(80000003de6000e7).
[  127.164258] mm/memory.c:391: bad pmd ffff880412e04ff8(80000003de0000e7).
[  127.186778] ------------[ cut here ]------------
[  127.186781] kernel BUG at mm/filemap.c:134!
[  127.186782] invalid opcode: 0000 [#1] SMP
[  127.186783] CPU 7
[  127.186784] Modules linked in: af_packet cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf ext3 jbd dm_mod coretemp crc32c_intel usb_storage ghash_clmulni_intel aesni_intel i2c_i801 r8169 mii uas sr_mod cdrom sg iTCO_wdt iTCO_vendor_support shpchp serio_raw cryptd aes_x86_64 e1000e pci_hotplug dcdbas aes_generic container microcode ext4 mbcache jbd2 crc16 sd_mod crc_t10dif i915 drm_kms_helper drm i2c_algo_bit ehci_hcd ahci libahci usbcore rtc_cmos usb_common button i2c_core intel_agp video intel_gtt fan processor thermal thermal_sys hwmon ata_generic pata_atiixp libata scsi_mod
[  127.186801]
[  127.186802] Pid: 9017, comm: hugetlbfs-test Not tainted 3.4.0-autobuild #53 Dell Inc. OptiPlex 990/06D7TR
[  127.186804] RIP: 0010:[<ffffffff810ed6ce>]  [<ffffffff810ed6ce>] __delete_from_page_cache+0x15e/0x160
[  127.186809] RSP: 0000:ffff8804144b5c08  EFLAGS: 00010002
[  127.186810] RAX: 0000000000000001 RBX: ffffea000a5c9000 RCX: 00000000ffffffc0
[  127.186811] RDX: 0000000000000000 RSI: 0000000000000009 RDI: ffff88042dfdad00
[  127.186812] RBP: ffff8804144b5c18 R08: 0000000000000009 R09: 0000000000000003
[  127.186813] R10: 0000000000000000 R11: 000000000000002d R12: ffff880412ff83d8
[  127.186814] R13: ffff880412ff83d8 R14: 0000000000000000 R15: ffff880412ff83d8
[  127.186815] FS:  00007fe18ed2c700(0000) GS:ffff88042dce0000(0000) knlGS:0000000000000000
[  127.186816] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  127.186817] CR2: 00007fe340000503 CR3: 0000000417a14000 CR4: 00000000000407e0
[  127.186818] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  127.186819] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  127.186820] Process hugetlbfs-test (pid: 9017, threadinfo ffff8804144b4000, task ffff880417f803c0)
[  127.186821] Stack:
[  127.186822]  ffffea000a5c9000 0000000000000000 ffff8804144b5c48 ffffffff810ed83b
[  127.186824]  ffff8804144b5c48 000000000000138a 0000000000001387 ffff8804144b5c98
[  127.186825]  ffff8804144b5d48 ffffffff811bc925 ffff8804144b5cb8 0000000000000000
[  127.186827] Call Trace:
[  127.186829]  [<ffffffff810ed83b>] delete_from_page_cache+0x3b/0x80
[  127.186832]  [<ffffffff811bc925>] truncate_hugepages+0x115/0x220
[  127.186834]  [<ffffffff811bca43>] hugetlbfs_evict_inode+0x13/0x30
[  127.186837]  [<ffffffff811655c7>] evict+0xa7/0x1b0
[  127.186839]  [<ffffffff811657a3>] iput_final+0xd3/0x1f0
[  127.186840]  [<ffffffff811658f9>] iput+0x39/0x50
[  127.186842]  [<ffffffff81162708>] d_kill+0xf8/0x130
[  127.186843]  [<ffffffff81162812>] dput+0xd2/0x1a0
[  127.186845]  [<ffffffff8114e2d0>] __fput+0x170/0x230
[  127.186848]  [<ffffffff81236e0e>] ? rb_erase+0xce/0x150
[  127.186849]  [<ffffffff8114e3ad>] fput+0x1d/0x30
[  127.186851]  [<ffffffff81117db7>] remove_vma+0x37/0x80
[  127.186853]  [<ffffffff81119182>] do_munmap+0x2d2/0x360
[  127.186855]  [<ffffffff811cc639>] sys_shmdt+0xc9/0x170
[  127.186857]  [<ffffffff81410a39>] system_call_fastpath+0x16/0x1b
[  127.186858] Code: 0f 1f 44 00 00 48 8b 43 08 48 8b 00 48 8b 40 28 8b b0 40 03 00 00 85 f6 0f 88 df fe ff ff 48 89 df e8 e7 cb 05 00 e9 d2 fe ff ff <0f> 0b 55 83 e2 fd 48 89 e5 48 83 ec 30 48 89 5d d8 4c 89 65 e0
[  127.186868] RIP  [<ffffffff810ed6ce>] __delete_from_page_cache+0x15e/0x160
[  127.186870]  RSP <ffff8804144b5c08>
[  127.186871] ---[ end trace 7cbac5d1db69f426 ]---

The bug is a race and not always easy to reproduce.  To reproduce it I was
doing the following on a single socket I7-based machine with 16G of RAM.

$ hugeadm --pool-pages-max DEFAULT:13G
$ echo $((18*1048576*1024)) > /proc/sys/kernel/shmmax
$ echo $((18*1048576*1024)) > /proc/sys/kernel/shmall
$ for i in `seq 1 9000`; do ./hugetlbfs-test; done

On my particular machine, it usually triggers within 10 minutes but
enabling debug options can change the timing such that it never hits.
Once the bug is triggered, the machine is in trouble and needs to be
rebooted.  The machine will respond but processes accessing proc like "ps
aux" will hang due to the BUG_ON.  shutdown will also hang and needs a
hard reset or a sysrq-b.

The basic problem is a race between page table sharing and teardown.  For
the most part page table sharing depends on i_mmap_mutex.  In some cases,
it is also taking the mm->page_table_lock for the PTE updates but with
shared page tables, it is the i_mmap_mutex that is more important.

Unfortunately it appears to be also insufficient. Consider the following
situation

Process A					Process B
---------					---------
hugetlb_fault					shmdt
  						LockWrite(mmap_sem)
    						  do_munmap
						    unmap_region
						      unmap_vmas
						        unmap_single_vma
						          unmap_hugepage_range
      						            Lock(i_mmap_mutex)
							    Lock(mm->page_table_lock)
							    huge_pmd_unshare/unmap tables <--- (1)
							    Unlock(mm->page_table_lock)
      						            Unlock(i_mmap_mutex)
  huge_pte_alloc				      ...
    Lock(i_mmap_mutex)				      ...
    vma_prio_walk, find svma, spte		      ...
    Lock(mm->page_table_lock)			      ...
    share spte					      ...
    Unlock(mm->page_table_lock)			      ...
    Unlock(i_mmap_mutex)			      ...
  hugetlb_no_page									  <--- (2)
						      free_pgtables
						        unlink_file_vma
							hugetlb_free_pgd_range
						    remove_vma_list

In this scenario, it is possible for Process A to share page tables with
Process B that is trying to tear them down.  The i_mmap_mutex on its own
does not prevent Process A walking Process B's page tables.  At (1) above,
the page tables are not shared yet so it unmaps the PMDs.  Process A sets
up page table sharing and at (2) faults a new entry.  Process B then trips
up on it in free_pgtables.

This patch fixes the problem by adding a new function
__unmap_hugepage_range_final that is only called when the VMA is about to
be destroyed.  This function clears VM_MAYSHARE during
unmap_hugepage_range() under the i_mmap_mutex.  This makes the VMA
ineligible for sharing and avoids the race.  Superficially this looks like
it would then be vunerable to truncate and madvise issues but hugetlbfs
has its own truncate handlers so does not use unmap_mapping_range() and
does not support madvise(DONTNEED).

This should be treated as a -stable candidate if it is merged.

Test program is as follows. The test case was mostly written by Michal
Hocko with a few minor changes to reproduce this bug.

==== CUT HERE ====

static size_t huge_page_size = (2UL << 20);
static size_t nr_huge_page_A = 512;
static size_t nr_huge_page_B = 5632;

unsigned int get_random(unsigned int max)
{
	struct timeval tv;

	gettimeofday(&tv, NULL);
	srandom(tv.tv_usec);
	return random() % max;
}

static void play(void *addr, size_t size)
{
	unsigned char *start = addr,
		      *end = start + size,
		      *a;
	start += get_random(size/2);

	/* we could itterate on huge pages but let's give it more time. */
	for (a = start; a < end; a += 4096)
		*a = 0;
}

int main(int argc, char **argv)
{
	key_t key = IPC_PRIVATE;
	size_t sizeA = nr_huge_page_A * huge_page_size;
	size_t sizeB = nr_huge_page_B * huge_page_size;
	int shmidA, shmidB;
	void *addrA = NULL, *addrB = NULL;
	int nr_children = 300, n = 0;

	if ((shmidA = shmget(key, sizeA, IPC_CREAT|SHM_HUGETLB|0660)) == -1) {
		perror("shmget:");
		return 1;
	}

	if ((addrA = shmat(shmidA, addrA, SHM_R|SHM_W)) == (void *)-1UL) {
		perror("shmat");
		return 1;
	}
	if ((shmidB = shmget(key, sizeB, IPC_CREAT|SHM_HUGETLB|0660)) == -1) {
		perror("shmget:");
		return 1;
	}

	if ((addrB = shmat(shmidB, addrB, SHM_R|SHM_W)) == (void *)-1UL) {
		perror("shmat");
		return 1;
	}

fork_child:
	switch(fork()) {
		case 0:
			switch (n%3) {
			case 0:
				play(addrA, sizeA);
				break;
			case 1:
				play(addrB, sizeB);
				break;
			case 2:
				break;
			}
			break;
		case -1:
			perror("fork:");
			break;
		default:
			if (++n < nr_children)
				goto fork_child;
			play(addrA, sizeA);
			break;
	}
	shmdt(addrA);
	shmdt(addrB);
	do {
		wait(NULL);
	} while (--n > 0);
	shmctl(shmidA, IPC_RMID, NULL);
	shmctl(shmidB, IPC_RMID, NULL);
	return 0;
}

[akpm@linux-foundation.org: name the declaration's args, fix CONFIG_HUGETLBFS=n build]
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:50 -07:00
Minchan Kim 6527af5d1b mm: remove redundant initialization
pg_data_t is zeroed before reaching free_area_init_core(), so remove the
now unnecessary initializations.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:50 -07:00
Johannes Weiner 0030f535a5 mm: memcg: fix compaction/migration failing due to memcg limits
Compaction (and page migration in general) can currently be hindered
through pages being owned by memory cgroups that are at their limits and
unreclaimable.

The reason is that the replacement page is being charged against the limit
while the page being replaced is also still charged.  But this seems
unnecessary, given that only one of the two pages will still be in use
after migration finishes.

This patch changes the memcg migration sequence so that the replacement
page is not charged.  Whatever page is still in use after successful or
failed migration gets to keep the charge of the page that was going to be
replaced.

The replacement page will still show up temporarily in the rss/cache
statistics, this can be fixed in a later patch as it's less urgent.

Reported-by: David Rientjes <rientjes@google.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Wanpeng Li <liwp.linux@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:48 -07:00
Mel Gorman a564b8f039 nfs: enable swap on NFS
Implement the new swapfile a_ops for NFS and hook up ->direct_IO.  This
will set the NFS socket to SOCK_MEMALLOC and run socket reconnect under
PF_MEMALLOC as well as reset SOCK_MEMALLOC before engaging the protocol
->connect() method.

PF_MEMALLOC should allow the allocation of struct socket and related
objects and the early (re)setting of SOCK_MEMALLOC should allow us to
receive the packets required for the TCP connection buildup.

[jlayton@redhat.com: Restore PF_MEMALLOC task flags in all cases]
[dfeng@redhat.com: Fix handling of multiple swap files]
[a.p.zijlstra@chello.nl: Original patch]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:48 -07:00
Mel Gorman 5a178119b0 mm: add support for direct_IO to highmem pages
The patch "mm: add support for a filesystem to activate swap files and use
direct_IO for writing swap pages" added support for using direct_IO to
write swap pages but it is insufficient for highmem pages.

To support highmem pages, this patch kmaps() the page before calling the
direct_IO() handler.  As direct_IO deals with virtual addresses an
additional helper is necessary for get_kernel_pages() to lookup the struct
page for a kmap virtual address.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:47 -07:00
Mel Gorman a509bc1a9e mm: swap: implement generic handler for swap_activate
The version of swap_activate introduced is sufficient for swap-over-NFS
but would not provide enough information to implement a generic handler.
This patch shuffles things slightly to ensure the same information is
available for aops->swap_activate() as is available to the core.

No functionality change.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:47 -07:00
Mel Gorman 62c230bc17 mm: add support for a filesystem to activate swap files and use direct_IO for writing swap pages
Currently swapfiles are managed entirely by the core VM by using ->bmap to
allocate space and write to the blocks directly.  This effectively ensures
that the underlying blocks are allocated and avoids the need for the swap
subsystem to locate what physical blocks store offsets within a file.

If the swap subsystem is to use the filesystem information to locate the
blocks, it is critical that information such as block groups, block
bitmaps and the block descriptor table that map the swap file were
resident in memory.  This patch adds address_space_operations that the VM
can call when activating or deactivating swap backed by a file.

  int swap_activate(struct file *);
  int swap_deactivate(struct file *);

The ->swap_activate() method is used to communicate to the file that the
VM relies on it, and the address_space should take adequate measures such
as reserving space in the underlying device, reserving memory for mempools
and pinning information such as the block descriptor table in memory.  The
->swap_deactivate() method is called on sys_swapoff() if ->swap_activate()
returned success.

After a successful swapfile ->swap_activate, the swapfile is marked
SWP_FILE and swapper_space.a_ops will proxy to
sis->swap_file->f_mappings->a_ops using ->direct_io to write swapcache
pages and ->readpage to read.

It is perfectly possible that direct_IO be used to read the swap pages but
it is an unnecessary complication.  Similarly, it is possible that
->writepage be used instead of direct_io to write the pages but filesystem
developers have stated that calling writepage from the VM is undesirable
for a variety of reasons and using direct_IO opens up the possibility of
writing back batches of swap pages in the future.

[a.p.zijlstra@chello.nl: Original patch]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:47 -07:00
Mel Gorman 18022c5d86 mm: add get_kernel_page[s] for pinning of kernel addresses for I/O
This patch adds two new APIs get_kernel_pages() and get_kernel_page() that
may be used to pin a vector of kernel addresses for IO.  The initial user
is expected to be NFS for allowing pages to be written to swap using
aops->direct_IO().  Strictly speaking, swap-over-NFS only needs to pin one
page for IO but it makes sense to express the API in terms of a vector and
add a helper for pinning single pages.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Cc: Mark Salter <msalter@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:47 -07:00
Mel Gorman f981c5950f mm: methods for teaching filesystems about PG_swapcache pages
In order to teach filesystems to handle swap cache pages, three new page
functions are introduced:

  pgoff_t page_file_index(struct page *);
  loff_t page_file_offset(struct page *);
  struct address_space *page_file_mapping(struct page *);

page_file_index() - gives the offset of this page in the file in
PAGE_CACHE_SIZE blocks.  Like page->index is for mapped pages, this
function also gives the correct index for PG_swapcache pages.

page_file_offset() - uses page_file_index(), so that it will give the
expected result, even for PG_swapcache pages.

page_file_mapping() - gives the mapping backing the actual page; that is
for swap cache pages it will give swap_file->f_mapping.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:47 -07:00
Mel Gorman 68243e76ee mm: account for the number of times direct reclaimers get throttled
Under significant pressure when writing back to network-backed storage,
direct reclaimers may get throttled.  This is expected to be a short-lived
event and the processes get woken up again but processes do get stalled.
This patch counts how many times such stalling occurs.  It's up to the
administrator whether to reduce these stalls by increasing
min_free_kbytes.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: David Miller <davem@davemloft.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:46 -07:00
Mel Gorman 5515061d22 mm: throttle direct reclaimers if PF_MEMALLOC reserves are low and swap is backed by network storage
If swap is backed by network storage such as NBD, there is a risk that a
large number of reclaimers can hang the system by consuming all
PF_MEMALLOC reserves.  To avoid these hangs, the administrator must tune
min_free_kbytes in advance which is a bit fragile.

This patch throttles direct reclaimers if half the PF_MEMALLOC reserves
are in use.  If the system is routinely getting throttled the system
administrator can increase min_free_kbytes so degradation is smoother but
the system will keep running.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: David Miller <davem@davemloft.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:46 -07:00
Mel Gorman 0614002bb5 netvm: propagate page->pfmemalloc from skb_alloc_page to skb
The skb->pfmemalloc flag gets set to true iff during the slab allocation
of data in __alloc_skb that the the PFMEMALLOC reserves were used.  If
page splitting is used, it is possible that pages will be allocated from
the PFMEMALLOC reserve without propagating this information to the skb.
This patch propagates page->pfmemalloc from pages allocated for fragments
to the skb.

It works by reintroducing and expanding the skb_alloc_page() API to take
an skb.  If the page was allocated from pfmemalloc reserves, it is
automatically copied.  If the driver allocates the page before the skb, it
should call skb_propagate_pfmemalloc() after the skb is allocated to
ensure the flag is copied properly.

Failure to do so is not critical.  The resulting driver may perform slower
if it is used for swap-over-NBD or swap-over-NFS but it should not result
in failure.

[davem@davemloft.net: API rename and consistency]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:46 -07:00
Mel Gorman c48a11c7ad netvm: propagate page->pfmemalloc to skb
The skb->pfmemalloc flag gets set to true iff during the slab allocation
of data in __alloc_skb that the the PFMEMALLOC reserves were used.  If the
packet is fragmented, it is possible that pages will be allocated from the
PFMEMALLOC reserve without propagating this information to the skb.  This
patch propagates page->pfmemalloc from pages allocated for fragments to
the skb.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:46 -07:00