Commit Graph

25624 Commits (23783f817bceedd6d4e549385e3f400ea64059e5)

Author SHA1 Message Date
Linus Torvalds a99cbf6b43 Merge branch 'kernel-doc' from Randy Dunlap
The usual kernel-doc fixups from Randy.  Some of them David acked as
merged in his tree, this is the random left-overs.

* kernel-doc:
  docbook: fix sched source file names in device-drivers book
  docbook: change iomap source filename in deviceiobook
  docbook: don't use serial_core.h in device-drivers book
  kernel-doc: fix kernel-doc warnings in sched
  kernel-doc: fix new warnings in cfg80211.h
  kernel-doc: fix new warning in usb.h
  kernel-doc: fix new warnings in device.h
  kernel-doc: fix new warnings in debugfs
  kernel-doc: fix new warning in regulator core
  kernel-doc: fix new warnings in pci
  kernel-doc: fix new warnings in driver-core
  kernel-doc: fix new warnings in auditsc.c
  scripts/kernel-doc: fix fatal error caused by cfg80211.h
2012-01-23 10:08:08 -08:00
Linus Torvalds 4f57d865f1 Merge branch 'akpm'
Quoth Andrew:
  "Random fixes.  And a simple new LED driver which I'm trying to sneak
   in while you're not looking."

Sneaking successful.

* akpm:
  score: fix off-by-one index into syscall table
  mm: fix rss count leakage during migration
  SHM_UNLOCK: fix Unevictable pages stranded after swap
  SHM_UNLOCK: fix long unpreemptible section
  kdump: define KEXEC_NOTE_BYTES arch specific for s390x
  mm/hugetlb.c: undo change to page mapcount in fault handler
  mm: memcg: update the correct soft limit tree during migration
  proc: clear_refs: do not clear reserved pages
  drivers/video/backlight/l4f00242t03.c: return proper error in l4f00242t03_probe if regulator_get() fails
  drivers/video/backlight/adp88x0_bl.c: fix bit testing logic
  kprobes: initialize before using a hlist
  ipc/mqueue: simplify reading msgqueue limit
  leds: add led driver for Bachmann's ot200
  mm: __count_immobile_pages(): make sure the node is online
  mm: fix NULL ptr dereference in __count_immobile_pages
  mm: fix warnings regarding enum migrate_mode
2012-01-23 09:27:54 -08:00
Linus Torvalds 7908b3ef68 Merge git://git.samba.org/sfrench/cifs-2.6
* git://git.samba.org/sfrench/cifs-2.6:
  CIFS: Rename *UCS* functions to *UTF16*
  [CIFS] ACL and FSCACHE support no longer EXPERIMENTAL
  [CIFS] Fix build break with multiuser patch when LANMAN disabled
  cifs: warn about impending deprecation of legacy MultiuserMount code
  cifs: fetch credentials out of keyring for non-krb5 auth multiuser mounts
  cifs: sanitize username handling
  keys: add a "logon" key type
  cifs: lower default wsize when unix extensions are not used
  cifs: better instrumentation for coalesce_t2
  cifs: integer overflow in parse_dacl()
  cifs: Fix sparse warning when calling cifs_strtoUCS
  CIFS: Add descriptions to the brlock cache functions
2012-01-23 08:59:49 -08:00
Randy Dunlap b5763accd3 kernel-doc: fix new warnings in debugfs
Fix new kernel-doc warnings:

Warning(fs/debugfs/file.c:556): No description found for parameter 'nregs'
Warning(fs/debugfs/file.c:556): Excess function parameter 'mregs' description in 'debugfs_print_regs32'

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-23 08:44:53 -08:00
Will Deacon 85e72aa538 proc: clear_refs: do not clear reserved pages
/proc/pid/clear_refs is used to clear the Referenced and YOUNG bits for
pages and corresponding page table entries of the task with PID pid, which
includes any special mappings inserted into the page tables in order to
provide things like vDSOs and user helper functions.

On ARM this causes a problem because the vectors page is mapped as a
global mapping and since ec706dab ("ARM: add a vma entry for the user
accessible vector page"), a VMA is also inserted into each task for this
page to aid unwinding through signals and syscall restarts.  Since the
vectors page is required for handling faults, clearing the YOUNG bit (and
subsequently writing a faulting pte) means that we lose the vectors page
*globally* and cannot fault it back in.  This results in a system deadlock
on the next exception.

To see this problem in action, just run:

	$ echo 1 > /proc/self/clear_refs

on an ARM platform (as any user) and watch your system hang.  I think this
has been the case since 2.6.37

This patch avoids clearing the aforementioned bits for reserved pages,
therefore leaving the vectors page intact on ARM.  Since reserved pages
are not candidates for swap, this change should not have any impact on the
usefulness of clear_refs.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Reported-by: Moussa Ba <moussaba@micron.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Acked-by: Nicolas Pitre <nico@linaro.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: <stable@vger.kernel.org>		[2.6.37+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-23 08:38:48 -08:00
Linus Torvalds 567e47935a Merge branches 'sched-urgent-for-linus', 'perf-urgent-for-linus' and 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/accounting, proc: Fix /proc/stat interrupts sum

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tracepoints/module: Fix disabling tracepoints with taint CRAP or OOT
  x86/kprobes: Add arch/x86/tools/insn_sanity to .gitignore
  x86/kprobes: Fix typo transferred from Intel manual

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, syscall: Need __ARCH_WANT_SYS_IPC for 32 bits
  x86, tsc: Fix SMI induced variation in quick_pit_calibrate()
  x86, opcode: ANDN and Group 17 in x86-opcode-map.txt
  x86/kconfig: Move the ZONE_DMA entry under a menu
  x86/UV2: Add accounting for BAU strong nacks
  x86/UV2: Ack BAU interrupt earlier
  x86/UV2: Remove stale no-resources test for UV2 BAU
  x86/UV2: Work around BAU bug
  x86/UV2: Fix BAU destination timeout initialization
  x86/UV2: Fix new UV2 hardware by using native UV2 broadcast mode
  x86: Get rid of dubious one-bit signed bitfield
2012-01-19 14:53:06 -08:00
Linus Torvalds e19c29e8d8 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  qnx4: don't leak ->BitMap on late failure exits
  qnx4: reduce the insane nesting in qnx4_checkroot()
  qnx4: di_fname is an array, for crying out loud...
  vfs: remove printk from set_nlink()
  wake up s_wait_unfrozen when ->freeze_fs fails
2012-01-19 14:49:16 -08:00
Al Viro 8bc5191b26 qnx4: don't leak ->BitMap on late failure exits
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-19 13:54:36 -05:00
Al Viro 4134bf81ff qnx4: reduce the insane nesting in qnx4_checkroot()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-19 13:40:57 -05:00
Al Viro 1aab323ea5 qnx4: di_fname is an array, for crying out loud...
(struct qnx4_inode_entry *)(bh->b_data + some_offset)->di_fname
is not going to be NULL, TYVM...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-19 13:19:42 -05:00
Steve French acbbb76a26 CIFS: Rename *UCS* functions to *UTF16*
to reflect the unicode encoding used by CIFS protocol.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Acked-by: Jeff Layton <jlayton@samba.org>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
2012-01-18 22:32:33 -06:00
Steve French c56001879b [CIFS] ACL and FSCACHE support no longer EXPERIMENTAL
CIFS ACL support and FSCACHE support have been in long enough
to be no longer considered experimental.  Remove obsolete Kconfig
dependency.

Signed-off-by: Steve French <sfrench@us.ibm.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
2012-01-18 17:55:41 -06:00
Steve French 88a4412b79 [CIFS] Fix build break with multiuser patch when LANMAN disabled
CC: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-01-18 17:13:47 -06:00
Jeff Layton 789b4588da cifs: warn about impending deprecation of legacy MultiuserMount code
We'll allow a grace period of 2 releases (3.3 and 3.4) and then remove
the legacy code in 3.5.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-01-17 22:40:31 -06:00
Jeff Layton 8a8798a5ff cifs: fetch credentials out of keyring for non-krb5 auth multiuser mounts
Fix up multiuser mounts to set the secType and set the username and
password from the key payload in the vol info for non-krb5 auth types.

Look for a key of type "secret" with a description of
"cifs🅰️<server address>" or "cifs:d:<domainname>". If that's found,
then scrape the username and password out of the key payload and use
that to create a new user session.

Finally, don't have the code enforce krb5 auth on multiuser mounts,
but do require a kernel with keys support.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-01-17 22:40:28 -06:00
Jeff Layton 04febabcf5 cifs: sanitize username handling
Currently, it's not very clear whether you're allowed to have a NULL
vol->username or ses->user_name. Some places check for it and some don't.

Make it clear that a NULL pointer is OK in these fields, and ensure that
all the callers check for that.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-01-17 22:40:26 -06:00
Jeff Layton ce91acb3ac cifs: lower default wsize when unix extensions are not used
We've had some reports of servers (namely, the Solaris in-kernel CIFS
server) that don't deal properly with writes that are "too large" even
though they set CAP_LARGE_WRITE_ANDX. Change the default to better
mirror what windows clients do.

Cc: stable@vger.kernel.org
Cc: Pavel Shilovsky <piastry@etersoft.ru>
Reported-by: Nick Davis <phireph0x@yahoo.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-01-17 22:39:37 -06:00
Jeff Layton f5fffcee27 cifs: better instrumentation for coalesce_t2
When coalesce_t2 returns an error, have it throw a cFYI message that
explains the reason. Also rename some variables to clarify what they
represent.

Reported-and-Tested-by: Konstantinos Skarlatos <k.skarlatos@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-01-17 22:39:34 -06:00
Linus Torvalds f429ee3b80 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit: (29 commits)
  audit: no leading space in audit_log_d_path prefix
  audit: treat s_id as an untrusted string
  audit: fix signedness bug in audit_log_execve_info()
  audit: comparison on interprocess fields
  audit: implement all object interfield comparisons
  audit: allow interfield comparison between gid and ogid
  audit: complex interfield comparison helper
  audit: allow interfield comparison in audit rules
  Kernel: Audit Support For The ARM Platform
  audit: do not call audit_getname on error
  audit: only allow tasks to set their loginuid if it is -1
  audit: remove task argument to audit_set_loginuid
  audit: allow audit matching on inode gid
  audit: allow matching on obj_uid
  audit: remove audit_finish_fork as it can't be called
  audit: reject entry,always rules
  audit: inline audit_free to simplify the look of generic code
  audit: drop audit_set_macxattr as it doesn't do anything
  audit: inline checks for not needing to collect aux records
  audit: drop some potentially inadvisable likely notations
  ...

Use evil merge to fix up grammar mistakes in Kconfig file.

Bad speling and horrible grammar (and copious swearing) is to be
expected, but let's keep it to commit messages and comments, rather than
expose it to users in config help texts or printouts.
2012-01-17 16:41:31 -08:00
Linus Torvalds 22b4eb5e31 Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs
* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: cleanup xfs_file_aio_write
  xfs: always return with the iolock held from xfs_file_aio_write_checks
  xfs: remove the i_new_size field in struct xfs_inode
  xfs: remove the i_size field in struct xfs_inode
  xfs: replace i_pin_wait with a bit waitqueue
  xfs: replace i_flock with a sleeping bitlock
  xfs: make i_flags an unsigned long
  xfs: remove the if_ext_max field in struct xfs_ifork
  xfs: remove the unused dm_attrs structure
  xfs: cleanup xfs_iomap_eof_align_last_fsb
  xfs: remove xfs_itruncate_data
2012-01-17 15:54:56 -08:00
Linus Torvalds d65773b22b Merge branch 'btrfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
* 'btrfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  btrfs: take allocation of ->tree_root into open_ctree()
  btrfs: let ->s_fs_info point to fs_info, not root...
  btrfs: consolidate failure exits in btrfs_mount() a bit
  btrfs: make free_fs_info() call ->kill_sb() unconditional
  btrfs: merge free_fs_info() calls on fill_super failures
  btrfs: kill pointless reassignment of ->s_fs_info in btrfs_fill_super()
  btrfs: make open_ctree() return int
  btrfs: sanitizing ->fs_info, part 5
  btrfs: sanitizing ->fs_info, part 4
  btrfs: sanitizing ->fs_info, part 3
  btrfs: sanitizing ->fs_info, part 2
  btrfs: sanitizing ->fs_info, part 1
  btrfs: fix a deadlock in btrfs_scan_one_device()
  btrfs: fix mount/umount race
  btrfs: get ->kill_sb() of its own
  btrfs: preparation to fixing mount/umount race
2012-01-17 15:52:51 -08:00
Linus Torvalds f9156c7288 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (62 commits)
  Btrfs: use larger system chunks
  Btrfs: add a delalloc mutex to inodes for delalloc reservations
  Btrfs: space leak tracepoints
  Btrfs: protect orphan block rsv with spin_lock
  Btrfs: add allocator tracepoints
  Btrfs: don't call btrfs_throttle in file write
  Btrfs: release space on error in page_mkwrite
  Btrfs: fix btrfsck error 400 when truncating a compressed
  Btrfs: do not use btrfs_end_transaction_throttle everywhere
  Btrfs: add balance progress reporting
  Btrfs: allow for resuming restriper after it was paused
  Btrfs: allow for canceling restriper
  Btrfs: allow for pausing restriper
  Btrfs: add skip_balance mount option
  Btrfs: recover balance on mount
  Btrfs: save balance parameters to disk
  Btrfs: soft profile changing mode (aka soft convert)
  Btrfs: implement online profile changing
  Btrfs: do not reduce profile in do_chunk_alloc()
  Btrfs: virtual address space subset filter
  ...

Fix up trivial conflict in fs/btrfs/ioctl.c due to the use of the new
mnt_drop_write_file() helper.
2012-01-17 15:49:54 -08:00
Linus Torvalds e268337dfe proc: clean up and fix /proc/<pid>/mem handling
Jüri Aedla reported that the /proc/<pid>/mem handling really isn't very
robust, and it also doesn't match the permission checking of any of the
other related files.

This changes it to do the permission checks at open time, and instead of
tracking the process, it tracks the VM at the time of the open.  That
simplifies the code a lot, but does mean that if you hold the file
descriptor open over an execve(), you'll continue to read from the _old_
VM.

That is different from our previous behavior, but much simpler.  If
somebody actually finds a load where this matters, we'll need to revert
this commit.

I suspect that nobody will ever notice - because the process mapping
addresses will also have changed as part of the execve.  So you cannot
actually usefully access the fd across a VM change simply because all
the offsets for IO would have changed too.

Reported-by: Jüri Aedla <asd@ut.ee>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-17 15:21:19 -08:00
Miklos Szeredi 424a5334a5 vfs: remove printk from set_nlink()
Don't log a message for set_nlink(0).

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-17 16:39:47 -05:00
Kazuya Mio e1616300a2 wake up s_wait_unfrozen when ->freeze_fs fails
dd slept infinitely when fsfeeze failed because of EIO.
To fix this problem, if ->freeze_fs fails, freeze_super() wakes up
the tasks waiting for the filesystem to become unfrozen.

When s_frozen isn't SB_UNFROZEN in __generic_file_aio_write(),
the function sleeps until FITHAW ioctl wakes up s_wait_unfrozen.

However, if ->freeze_fs fails, s_frozen is set to SB_UNFROZEN and then
freeze_super() returns an error number. In this case, FITHAW ioctl returns
EINVAL because s_frozen is already SB_UNFROZEN. There is no way to wake up
s_wait_unfrozen, so __generic_file_aio_write() sleeps infinitely.

Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-17 16:38:47 -05:00
Eric Paris 4043cde8ec audit: do not call audit_getname on error
Just a code cleanup really.  We don't need to make a function call just for
it to return on error.  This also makes the VFS function even easier to follow
and removes a conditional on a hot path.

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-01-17 16:17:01 -05:00
Eric Paris 633b454545 audit: only allow tasks to set their loginuid if it is -1
At the moment we allow tasks to set their loginuid if they have
CAP_AUDIT_CONTROL.  In reality we want tasks to set the loginuid when they
log in and it be impossible to ever reset.  We had to make it mutable even
after it was once set (with the CAP) because on update and admin might have
to restart sshd.  Now sshd would get his loginuid and the next user which
logged in using ssh would not be able to set his loginuid.

Systemd has changed how userspace works and allowed us to make the kernel
work the way it should.  With systemd users (even admins) are not supposed
to restart services directly.  The system will restart the service for
them.  Thus since systemd is going to loginuid==-1, sshd would get -1, and
sshd would be allowed to set a new loginuid without special permissions.

If an admin in this system were to manually start an sshd he is inserting
himself into the system chain of trust and thus, logically, it's his
loginuid that should be used!  Since we have old systems I make this a
Kconfig option.

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-01-17 16:17:00 -05:00
Eric Paris 0a300be6d5 audit: remove task argument to audit_set_loginuid
The function always deals with current.  Don't expose an option
pretending one can use it for something.  You can't.

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-01-17 16:17:00 -05:00
Christoph Hellwig d060646436 xfs: cleanup xfs_file_aio_write
With all the size field updates out of the way xfs_file_aio_write can
be further simplified by pushing all iolock handling into
xfs_file_dio_aio_write and xfs_file_buffered_aio_write and using
the generic generic_write_sync helper for synchronous writes.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-17 15:12:33 -06:00
Christoph Hellwig 5bf1f26227 xfs: always return with the iolock held from xfs_file_aio_write_checks
While xfs_iunlock is fine with 0 lockflags the calling conventions are much
cleaner if xfs_file_aio_write_checks never returns without the iolock held.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-17 15:11:07 -06:00
Christoph Hellwig 2813d682e8 xfs: remove the i_new_size field in struct xfs_inode
Now that we use the VFS i_size field throughout XFS there is no need for the
i_new_size field any more given that the VFS i_size field gets updated
in ->write_end before unlocking the page, and thus is always uptodate when
writeback could see a page.  Removing i_new_size also has the advantage that
we will never have to trim back di_size during a failed buffered write,
given that it never gets updated past i_size.

Note that currently the generic direct I/O code only updates i_size after
calling our end_io handler, which requires a small workaround to make
sure di_size actually makes it to disk.  I hope to fix this properly in
the generic code.

A downside is that we lose the support for parallel non-overlapping O_DIRECT
appending writes that recently was added.  I don't think keeping the complex
and fragile i_new_size infrastructure for this is a good tradeoff - if we
really care about parallel appending writers we should investigate turning
the iolock into a range lock, which would also allow for parallel
non-overlapping buffered writers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-17 15:10:19 -06:00
Christoph Hellwig ce7ae151dd xfs: remove the i_size field in struct xfs_inode
There is no fundamental need to keep an in-memory inode size copy in the XFS
inode.  We already have the on-disk value in the dinode, and the separate
in-memory copy that we need for regular files only in the XFS inode.

Remove the xfs_inode i_size field and change the XFS_ISIZE macro to use the
VFS inode i_size field for regular files.  Switch code that was directly
accessing the i_size field in the xfs_inode to XFS_ISIZE, or in cases where
we are limited to regular files direct access of the VFS inode i_size field.

This also allows dropping some fairly complicated code in the write path
which dealt with keeping the xfs_inode i_size uptodate with the VFS i_size
that is getting updated inside ->write_end.

Note that we do not bother resetting the VFS i_size when truncating a file
that gets freed to zero as there is no point in doing so because the VFS inode
is no longer in use at this point.  Just relax the assert in xfs_ifree to
only check the on-disk size instead.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-17 15:08:53 -06:00
Christoph Hellwig f392e6319a xfs: replace i_pin_wait with a bit waitqueue
Replace i_pin_wait, which is only used during synchronous inode flushing
with a bit waitqueue.  This trades off a much smaller inode against
slightly slower wakeup performance, and saves 12 (32-bit) or 20 (64-bit)
bytes in the XFS inode.

Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-17 15:07:54 -06:00
Christoph Hellwig 474fce0675 xfs: replace i_flock with a sleeping bitlock
We almost never block on i_flock, the exception is synchronous inode
flushing.  Instead of bloating the inode with a 16/24-byte completion
that we abuse as a semaphore just implement it as a bitlock that uses
a bit waitqueue for the rare sleeping path.  This primarily is a
tradeoff between a much smaller inode and a faster non-blocking
path vs faster wakeups, and we are much better off with the former.

A small downside is that we will lose lockdep checking for i_flock, but
given that it's always taken inside the ilock that should be acceptable.

Note that for example the inode writeback locking is implemented in a
very similar way.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-17 15:06:45 -06:00
Christoph Hellwig 49e4c70e52 xfs: make i_flags an unsigned long
To be used for bit wakeup i_flags needs to be an unsigned long or we'll
run into trouble on big endian systems.  Because of the 1-byte i_update
field right after it this actually causes a fairly large size increase
on its own (4 or 8 bytes), but that increase will be more than offset
by the next two patches.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-17 15:03:50 -06:00
Christoph Hellwig 8096b1ebb5 xfs: remove the if_ext_max field in struct xfs_ifork
We spent a lot of effort to maintain this field, but it always equals to the
fork size divided by the constant size of an extent.  The prime use of it is
to assert that the two stay in sync.  Just divide the fork size by the extent
size in the few places that we actually use it and remove the overhead
of maintaining it.  Also introduce a few helpers to consolidate the places
where we actually care about the value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-17 15:02:28 -06:00
Linus Torvalds a12587b003 NFS client bugfixes and cleanups for Linux 3.3 (pull 2)
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Merge tag 'nfs-for-3.3-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

NFS client bugfixes and cleanups for Linux 3.3 (pull 2)

* tag 'nfs-for-3.3-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  pnfsblock: alloc short extent before submit bio
  pnfsblock: remove rpc_call_ops from struct parallel_io
  pnfsblock: move find lock page logic out of bl_write_pagelist
  pnfsblock: cleanup bl_mark_sectors_init
  pnfsblock: limit bio page count
  pnfsblock: don't spinlock when freeing block_dev
  pnfsblock: clean up _add_entry
  pnfsblock: set read/write tk_status to pnfs_error
  pnfsblock: acquire im_lock in _preload_range
  NFS4: fix compile warnings in nfs4proc.c
  nfs: check for integer overflow in decode_devicenotify_args()
  NFS: cleanup endian type in decode_ds_addr()
  NFS: add an endian notation
2012-01-16 15:08:13 -08:00
Chris Mason 96bdc7dc61 Btrfs: use larger system chunks
system chunks by default are very small.  This makes them slightly
larger and also fixes the conditional checks to make sure we don't
allocate a billion of them at once.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-01-16 15:38:24 -05:00
Josef Bacik f248679e86 Btrfs: add a delalloc mutex to inodes for delalloc reservations
I was using i_mutex for this, but we're getting bogus lockdep warnings by doing
that and theres no real way to get rid of those, so just stop using i_mutex to
protect delalloc metadata reservations and use a delalloc mutex instead.  This
shouldn't be contended often at all, only if you are writing and mmap writing to
the file at the same time.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-01-16 15:29:43 -05:00
Josef Bacik 8c2a3ca20f Btrfs: space leak tracepoints
This in addition to a script in my btrfs-tracing tree will help track down space
leaks when we're getting space left over in block groups on umount.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-01-16 15:29:43 -05:00
Josef Bacik 90290e1982 Btrfs: protect orphan block rsv with spin_lock
We've been seeing warnings coming out of the orphan commit stuff forever from
ceph.  Turns out it's because we're racing with checking if the orphan block
reserve is set, because we clear it outside of the spin_lock.  So leave the
normal fastpath checks where they are, but take the spin_lock and _recheck_ to
make sure we haven't had an orphan block rsv added in the meantime.  Then clear
the root's orphan block rsv and release the lock.  With this patch a user said
the warnings went away and they usually showed up pretty soon after he started
ceph.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-01-16 15:29:42 -05:00
Josef Bacik 3f7de037fb Btrfs: add allocator tracepoints
I used these tracepoints when figuring out what the cluster stuff was doing, so
add them to mainline in case we need to profile this stuff again.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-01-16 15:29:42 -05:00
Josef Bacik 45a8090e62 Btrfs: don't call btrfs_throttle in file write
Btrfs_throttle will make us wait if there is a currently committing transaction
until we can open new transactions, which is ridiculous since we don't actually
start any transactions within the file write path anyway, so all this does is
introduce big latencies if we have a sync/fsync heavy workload going on while
somebody else is trying to do work.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-01-16 15:28:55 -05:00
Josef Bacik ec39e180fd Btrfs: release space on error in page_mkwrite
If updating the inode gave us an ENOSPC we were just returning in page_mkwrite,
which is a problem since we make our reservation right before trying to update
the inode, so fix the out label so that we actually free our reservation.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-01-16 15:28:54 -05:00
Miao Xie f70a9a6b94 Btrfs: fix btrfsck error 400 when truncating a compressed
Reproduce steps:
 # mkfs.btrfs /dev/sdb5
 # mount /dev/sdb5 -o compress=lzo /mnt
 # dd if=/dev/zero of=/mnt/tmpfile bs=128K count=1
 # sync
 # truncate -s 64K /mnt/tmpfile
 root 5 inode 257 errors 400

This is because of the wrong if condition, which is used to check if we should
subtract the bytes of the dropped range from i_blocks/i_bytes of i-node or not.
When we truncate a compressed extent, btrfs substracts the bytes of the whole
extent, it's wrong. We should substract the real size that we truncate, no
matter it is a compressed extent or not. Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-01-16 15:28:54 -05:00
Josef Bacik 7ad85bb76a Btrfs: do not use btrfs_end_transaction_throttle everywhere
A user reported a problem where things like open with O_CREAT would take up to
30 seconds when he had nfs activity on the same mount.  This is because all of
our quick metadata operations, like create, symlink etc all do
btrfs_end_transaction_throttle, which if the transaction is blocked will wait
for the commit to complete before it returns.  This adds a ridiculous amount of
latency and isn't really needed.  The normal btrfs_end_transaction will mark the
transaction as blocked and wake the transaction kthread up if it thinks the
transaction needs to end (this being in the running out of global reserve space
scenario), and this is all that is really needed since we've already done
everything we're going to do, we just need to return.  This should help people
with the latency they were seeing when using synchronous heavy workloads.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-01-16 15:28:54 -05:00
Chris Mason c126dea771 Merge branch 'integrity-check-patch-v2' of git://btrfs.giantdisaster.de/git/btrfs into integration
Conflicts:
	fs/btrfs/ctree.h
	fs/btrfs/super.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-01-16 15:27:58 -05:00
Chris Mason 9785dbdf26 Merge branch 'for-chris' of git://git.jan-o-sch.net/btrfs-unstable into integration 2012-01-16 15:26:31 -05:00
Chris Mason d756bd2d93 Merge branch 'for-chris' of git://repo.or.cz/linux-btrfs-devel into integration
Conflicts:
	fs/btrfs/volumes.c

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-01-16 15:26:17 -05:00
Chris Mason 27263e2832 Merge branch 'restriper' of git://github.com/idryomov/btrfs-unstable into integration 2012-01-16 15:26:02 -05:00
Chris Mason 64e05503ab Merge branch 'allocation-fixes' into integration 2012-01-16 15:25:42 -05:00
Ilya Dryomov 19a39dce3b Btrfs: add balance progress reporting
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:49 +02:00
Ilya Dryomov de322263d3 Btrfs: allow for resuming restriper after it was paused
Recognize BTRFS_BALANCE_RESUME flag passed from userspace.  We use the
same heuristics used when recovering balance after a crash to try to
start where we left off last time.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:49 +02:00
Ilya Dryomov a7e99c691a Btrfs: allow for canceling restriper
Implement an ioctl for canceling restriper.  Currently we wait until
relocation of the current block group is finished, in future this can be
done by triggering a commit.  Balance item is deleted and no memory
about the interrupted balance is kept.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:49 +02:00
Ilya Dryomov 837d5b6e46 Btrfs: allow for pausing restriper
Implement an ioctl for pausing restriper.  This pauses the relocation,
but balance is still considered to be "in progress": balance item is
not deleted, other volume operations cannot be started, etc.  If paused
in the middle of profile changing operation we will continue making
allocations with the target profile.

Add a hook to close_ctree() to pause restriper and free its data
structures on unmount.  (It's safe to unmount when restriper is in
"paused" state, we will resume with the same parameters on the next
mount)

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:49 +02:00
Ilya Dryomov 9555c6c180 Btrfs: add skip_balance mount option
Since restriper kthread starts involuntarily on mount and can suck cpu
and memory bandwidth add a mount option to forcefully skip it.  The
restriper in that case hangs around in paused state and can be resumed
from userspace when it's convenient.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:48 +02:00
Ilya Dryomov 596410151e Btrfs: recover balance on mount
On mount, if balance item is found, resume balance in a separate
kernel thread.

Try to be smart to continue roughly where previous balance (or convert)
was interrupted.  For chunk types that were being converted to some
profile we turn on soft convert, in case of a simple balance we turn on
usage filter and relocate only less-than-90%-full chunks of that type.
These are just heuristics but they help quite a bit, and can be improved
in future.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:48 +02:00
Ilya Dryomov 0940ebf6b9 Btrfs: save balance parameters to disk
Introduce a new btree objectid for storing balance item.  The reason is
to be able to resume restriper after a crash with the same parameters.
Balance item has a very high objectid and goes into tree of tree roots.

The key for the new item is as follows:

	[ BTRFS_BALANCE_OBJECTID ; BTRFS_BALANCE_ITEM_KEY ; 0 ]

Older kernels simply ignore it so it's safe to mount with an older
kernel and then go back to the newer one.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:48 +02:00
Ilya Dryomov cfa4c961cc Btrfs: soft profile changing mode (aka soft convert)
When doing convert from one profile to another if soft mode is on
restriper won't touch chunks that already have the profile we are
converting to.  This is useful if e.g. half of the FS was converted
earlier.

The soft mode switch is (like every other filter) per-type.  This means
that we can convert for example meta chunks the "hard" way while
converting data chunks selectively with soft switch.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:48 +02:00
Ilya Dryomov e4d8ec0f65 Btrfs: implement online profile changing
Profile changing is done by launching a balance with
BTRFS_BALANCE_CONVERT bits set and target fields of respective
btrfs_balance_args structs initialized.  Profile reducing code in this
case will pick restriper's target profile if it's available instead of
doing a blind reduce.  If target profile is not yet available it goes
back to a plain reduce.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:48 +02:00
Ilya Dryomov 70922617b0 Btrfs: do not reduce profile in do_chunk_alloc()
Every caller of do_chunk_alloc() feeds it the reduced allocation
profile, so stop trying to reduce it one more time.  Instead check the
validity of the passed profile.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:48 +02:00
Ilya Dryomov ea67176ae8 Btrfs: virtual address space subset filter
Select chunks which have at least one byte located inside a given
[vstart, vend) virtual address space range.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:48 +02:00
Ilya Dryomov 94e60d5a5c Btrfs: devid subset filter
Select chunks which have at least one byte of at least one stripe
located on a device with devid X in a given [pstart,pend) physical
address range.

This filter only works when devid filter is turned on.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:48 +02:00
Ilya Dryomov 409d404b46 Btrfs: devid filter
Relocate chunks which have at least one stripe located on a device with
devid X.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:47 +02:00
Ilya Dryomov 5ce5b3c091 Btrfs: usage filter
Select chunks that are less than X percent full.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:47 +02:00
Ilya Dryomov ed25e9b26f Btrfs: profiles filter
Select chunks based on a given profile mask.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:47 +02:00
Ilya Dryomov f43ffb60fd Btrfs: add basic infrastructure for selective balancing
This allows to have a separate set of filters for each chunk type
(data,meta,sys).  The code however is generic and switch on chunk type
is only done once.

This commit also adds a type filter: it allows to balance for example
meta and system chunks w/o touching data ones.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:47 +02:00
Ilya Dryomov c9e9f97bdf Btrfs: add basic restriper infrastructure
Add basic restriper infrastructure: extended balancing ioctl and all
related ioctl data structures, add data structure for tracking
restriper's state to fs_info, etc.  The semantics of the old balancing
ioctl are fully preserved.

Explicitly disallow any volume operations when balance is in progress.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:47 +02:00
Ilya Dryomov 10ea00f55a Btrfs: make avail_*_alloc_bits fields dynamic
Currently when new chunks are created respective avail_alloc_bits field
is updated to reflect profiles of all chunks present in the system.
However when chunks are removed profile bits are never cleared.

This patch clears profile bit of respective avail_alloc_bits field when
the last chunk with that profile is removed.  Restriper needs this to
properly operate when "downgrading".

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:47 +02:00
Ilya Dryomov a46d11a8b0 Btrfs: add BTRFS_AVAIL_ALLOC_BIT_SINGLE bit
Right now on-disk BTRFS_BLOCK_GROUP_* profile bits are used for
avail_{data,metadata,system}_alloc_bits fields, which gather info about
available allocation profiles in the FS.  When chunk is created or read
from disk, its profile is OR'ed with the corresponding avail_alloc_bits
field.  Since SINGLE is denoted by 0 in the on-disk format, currently
there is no way to tell when such chunks become avaialble.  Restriper
needs that information, so add a separate bit for SINGLE profile.

This bit is going to be in-memory only, it should never be written out
to disk, so it's not a disk format change.  However to avoid remappings
in future, reserve corresponding on-disk bit.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:47 +02:00
Ilya Dryomov 52ba692972 Btrfs: introduce masks for chunk type and profile
Chunk's type and profile are encoded in u64 flags field.  Introduce
masks to easily access them.  Also fix the type of BTRFS_BLOCK_GROUP_*
constants, it should be ULL.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:47 +02:00
Ilya Dryomov 6fef8df1dc Btrfs: get rid of *_alloc_profile fields
{data,metadata,system}_alloc_profile fields have been unused for a long
time now.  Get rid of them.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:47 +02:00
Russell King f7e6746eba sched/accounting, proc: Fix /proc/stat interrupts sum
Commit 3292beb340 ("sched/accounting: Change cpustat fields to an array")
deleted the code which provides us with the sum of all interrupts in the
system, causing vmstat to report zero interrupts occuring in the system.

Fix this by restoring the code.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk> # [on ARM]
Tested-by: Tony Luck <tony.luck@intel.com>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Glauber Costa <glommer@parallels.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Tuner <pjt@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-16 08:13:27 +01:00
Linus Torvalds 122804ecb5 Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (655 commits)
  [media] revert patch: HDIC HD29L2 DMB-TH USB2.0 reference design driver
  mb86a20s: Add a few more register settings at the init seq
  mb86a20s: Group registers into the same line
  [media] [PATCH] don't reset the delivery system on DTV_CLEAR
  [media] [BUG] it913x-fe fix typo error making SNR levels unstable
  [media] cx23885: Query the CX25840 during enum_input for status
  [media] cx25840: Add support for g_input_status
  [media] rc-videomate-m1f.c Rename to match remote controler name
  [media] drivers: media: au0828: Fix dependency for VIDEO_AU0828
  [media] convert drivers/media/* to use module_platform_driver()
  [media] drivers: video: cx231xx: Fix dependency for VIDEO_CX231XX_DVB
  [media] Exynos4 JPEG codec v4l2 driver
  [media] doc: v4l: selection: choose pixels as units for selection rectangles
  [media] v4l: s5p-tv: mixer: fix setup of VP scaling
  [media] v4l: s5p-tv: mixer: add support for selection API
  [media] v4l: emulate old crop API using extended crop/compose API
  [media] doc: v4l: add documentation for selection API
  [media] doc: v4l: add binary images for selection API
  [media] v4l: add support for selection api
  [media] hd29l2: fix review findings
  ...
2012-01-15 12:49:56 -08:00
Linus Torvalds b3c9dd182e Merge branch 'for-3.3/core' of git://git.kernel.dk/linux-block
* 'for-3.3/core' of git://git.kernel.dk/linux-block: (37 commits)
  Revert "block: recursive merge requests"
  block: Stop using macro stubs for the bio data integrity calls
  blockdev: convert some macros to static inlines
  fs: remove unneeded plug in mpage_readpages()
  block: Add BLKROTATIONAL ioctl
  block: Introduce blk_set_stacking_limits function
  block: remove WARN_ON_ONCE() in exit_io_context()
  block: an exiting task should be allowed to create io_context
  block: ioc_cgroup_changed() needs to be exported
  block: recursive merge requests
  block, cfq: fix empty queue crash caused by request merge
  block, cfq: move icq creation and rq->elv.icq association to block core
  block, cfq: restructure io_cq creation path for io_context interface cleanup
  block, cfq: move io_cq exit/release to blk-ioc.c
  block, cfq: move icq cache management to block core
  block, cfq: move io_cq lookup to blk-ioc.c
  block, cfq: move cfqd->icq_list to request_queue and add request->elv.icq
  block, cfq: reorganize cfq_io_context into generic and cfq specific parts
  block: remove elevator_queue->ops
  block: reorder elevator switch sequence
  ...

Fix up conflicts in:
 - block/blk-cgroup.c
	Switch from can_attach_task to can_attach
 - block/cfq-iosched.c
	conflict with now removed cic index changes (we now use q->id instead)
2012-01-15 12:24:45 -08:00
Linus Torvalds a520458fcc Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6
* 'linux-next' of git://git.infradead.org/ubifs-2.6:
  UBI: use own macros for the layout volume
  UBI: fix nameless volumes handling
  UBIFS: fix non-debug configuration build
2012-01-15 11:25:41 -08:00
Dominique Martinet e234b5f207 UBIFS: fix non-debug configuration build
Fix a brown paperbag bug introduced by me in the previous commit. I was
in hurry and forgot about the non-debug case completely.

Artem: amend the commit message and tweak the patch to preserve alignment.
       This made the patch a bit less readable, though.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
2012-01-15 13:46:02 +02:00
Linus Torvalds c49c41a413 Merge branch 'for-linus' of git://selinuxproject.org/~jmorris/linux-security
* 'for-linus' of git://selinuxproject.org/~jmorris/linux-security:
  capabilities: remove __cap_full_set definition
  security: remove the security_netlink_recv hook as it is equivalent to capable()
  ptrace: do not audit capability check when outputing /proc/pid/stat
  capabilities: remove task_ns_* functions
  capabitlies: ns_capable can use the cap helpers rather than lsm call
  capabilities: style only - move capable below ns_capable
  capabilites: introduce new has_ns_capabilities_noaudit
  capabilities: call has_ns_capability from has_capability
  capabilities: remove all _real_ interfaces
  capabilities: introduce security_capable_noaudit
  capabilities: reverse arguments to security_capable
  capabilities: remove the task from capable LSM hook entirely
  selinux: sparse fix: fix several warnings in the security server cod
  selinux: sparse fix: fix warnings in netlink code
  selinux: sparse fix: eliminate warnings for selinuxfs
  selinux: sparse fix: declare selinux_disable() in security.h
  selinux: sparse fix: move selinux_complete_init
  selinux: sparse fix: make selinux_secmark_refcount static
  SELinux: Fix RCU deref check warning in sel_netport_insert()

Manually fix up a semantic mis-merge wrt security_netlink_recv():

 - the interface was removed in commit fd77846152 ("security: remove
   the security_netlink_recv hook as it is equivalent to capable()")

 - a new user of it appeared in commit a38f7907b9 ("crypto: Add
   userspace configuration API")

causing no automatic merge conflict, but Eric Paris pointed out the
issue.
2012-01-14 18:36:33 -08:00
Miklos Szeredi fed474857e fsnotify: don't BUG in fsnotify_destroy_mark()
Removing the parent of a watched file results in "kernel BUG at
fs/notify/mark.c:139".

To reproduce

  add "-w /tmp/audit/dir/watched_file" to audit.rules
  rm -rf /tmp/audit/dir

This is caused by fsnotify_destroy_mark() being called without an
extra reference taken by the caller.

Reported by Francesco Cosoleto here:

  https://bugzilla.novell.com/show_bug.cgi?id=689860

Fix by removing the BUG_ON and adding a comment about not accessing mark after
the iput.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-14 18:01:42 -08:00
Linus Torvalds 0a80939b3e Autogenerated GPG tag for Rusty D1ADB8F1: 15EE 8D6C AB0E 7F0C F999 BFCB D920 0E6C D1AD B8F1
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Merge tag 'for-linus' of git://github.com/rustyrussell/linux

Autogenerated GPG tag for Rusty D1ADB8F1: 15EE 8D6C AB0E 7F0C F999  BFCB D920 0E6C D1AD B8F1

* tag 'for-linus' of git://github.com/rustyrussell/linux:
  module_param: check that bool parameters really are bool.
  intelfbdrv.c: bailearly is an int module_param
  paride/pcd: fix bool verbose module parameter.
  module_param: make bool parameters really bool (drivers & misc)
  module_param: make bool parameters really bool (arch)
  module_param: make bool parameters really bool (core code)
  kernel/async: remove redundant declaration.
  printk: fix unnecessary module_param_name.
  lirc_parallel: fix module parameter description.
  module_param: avoid bool abuse, add bint for special cases.
  module_param: check type correctness for module_param_array
  modpost: use linker section to generate table.
  modpost: use a table rather than a giant if/else statement.
  modules: sysfs - export: taint, coresize, initsize
  kernel/params: replace DEBUGP with pr_debug
  module: replace DEBUGP with pr_debug
  module: struct module_ref should contains long fields
  module: Fix performance regression on modules with large symbol tables
  module: Add comments describing how the "strmap" logic works

Fix up conflicts in scripts/mod/file2alias.c due to the new linker-
generated table approach to adding __mod_*_device_table entries.  The
ARM sa11x0 mcp bus needed to be converted to that too.
2012-01-14 12:32:16 -08:00
Linus Torvalds 0b48d42235 Merge branch 'for-3.3' of git://linux-nfs.org/~bfields/linux
* 'for-3.3' of git://linux-nfs.org/~bfields/linux: (31 commits)
  nfsd4: nfsd4_create_clid_dir return value is unused
  NFSD: Change name of extended attribute containing junction
  svcrpc: don't revert to SVC_POOL_DEFAULT on nfsd shutdown
  svcrpc: fix double-free on shutdown of nfsd after changing pool mode
  nfsd4: be forgiving in the absence of the recovery directory
  nfsd4: fix spurious 4.1 post-reboot failures
  NFSD: forget_delegations should use list_for_each_entry_safe
  NFSD: Only reinitilize the recall_lru list under the recall lock
  nfsd4: initialize special stateid's at compile time
  NFSd: use network-namespace-aware cache registering routines
  SUNRPC: create svc_xprt in proper network namespace
  svcrpc: update outdated BKL comment
  nfsd41: allow non-reclaim open-by-fh's in 4.1
  svcrpc: avoid memory-corruption on pool shutdown
  svcrpc: destroy server sockets all at once
  svcrpc: make svc_delete_xprt static
  nfsd: Fix oops when parsing a 0 length export
  nfsd4: Use kmemdup rather than duplicating its implementation
  nfsd4: add a separate (lockowner, inode) lookup
  nfsd4: fix CONFIG_NFSD_FAULT_INJECTION compile error
  ...
2012-01-14 12:26:41 -08:00
Gleb Natapov 69e4747ee9 Unused iocbs in a batch should not be accounted as active.
Since commit 080d676de0 ("aio: allocate kiocbs in batches") iocbs are
allocated in a batch during processing of first iocbs.  All iocbs in a
batch are automatically added to ctx->active_reqs list and accounted in
ctx->reqs_active.

If one (not the last one) of iocbs submitted by an user fails, further
iocbs are not processed, but they are still present in ctx->active_reqs
and accounted in ctx->reqs_active.  This causes process to stuck in a D
state in wait_for_all_aios() on exit since ctx->reqs_active will never
go down to zero.  Furthermore since kiocb_batch_free() frees iocb
without removing it from active_reqs list the list become corrupted
which may cause oops.

Fix this by removing iocb from ctx->active_reqs and updating
ctx->reqs_active in kiocb_batch_free().

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Cc: stable@kernel.org   # 3.2
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-13 20:39:44 -08:00
Linus Torvalds 96e80a7851 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next
* git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next:
  Squashfs: fix i_blocks calculation with extended regular files
  Squashfs: fix mount time sanity check for corrupted superblock
  Squashfs: optimise squashfs_cache_get entry search
  Squashfs: Update documentation to include xattrs
  Squashfs: add missing block release on error condition
2012-01-13 10:34:57 -08:00
Linus Torvalds 57e6a7dde8 Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw:
  GFS2: Fix nlink setting on inode creation
  GFS2: fail mount if journal recovery fails
  GFS2: let spectator mount do read only recovery
  GFS2: Fix a use-after-free that coverity spotted
  GFS2: dlm based recovery coordination
2012-01-13 10:33:39 -08:00
Linus Torvalds 94b1984ab9 Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6
* 'linux-next' of git://git.infradead.org/ubifs-2.6:
  UBIFS: fix key printing
  UBIFS: use snprintf instead of sprintf when printing keys
  UBIFS: fix debugging messages
  UBIFS: make debugging messages light again
  UBI: fix debugging messages
  UBI: make vid_hdr non-static
2012-01-13 10:31:33 -08:00
Linus Torvalds 1a52bb0b68 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  ceph: ensure prealloc_blob is in place when removing xattr
  rbd: initialize snap_rwsem in rbd_add()
  ceph: enable/disable dentry complete flags via mount option
  vfs: export symbol d_find_any_alias()
  ceph: always initialize the dentry in open_root_dentry()
  libceph: remove useless return value for osd_client __send_request()
  ceph: avoid iput() while holding spinlock in ceph_dir_fsync
  ceph: avoid useless dget/dput in encode_fh
  ceph: dereference pointer after checking for NULL
  crush: fix force for non-root TAKE
  ceph: remove unnecessary d_fsdata conditional checks
  ceph: Use kmemdup rather than duplicating its implementation

Fix up conflicts in fs/ceph/super.c (d_alloc_root() failure handling vs
always initialize the dentry in open_root_dentry)
2012-01-13 10:29:21 -08:00
Christoph Hellwig 3d2b3129c2 xfs: remove the unused dm_attrs structure
.. and the just as dead bhv_desc forward declaration while we're at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-13 12:11:46 -06:00
Christoph Hellwig bf322d983e xfs: cleanup xfs_iomap_eof_align_last_fsb
Replace the nasty if, else if, elseif condition with more natural C flow
that expressed the logic we want here better.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-13 12:11:46 -06:00
Christoph Hellwig 673e8e597c xfs: remove xfs_itruncate_data
This wrapper isn't overly useful, not to say rather confusing.

Around the call to xfs_itruncate_extents it does:

 - add tracing
 - add a few asserts in debug builds
 - conditionally update the inode size in two places
 - log the inode

Both the tracing and the inode logging can be moved to xfs_itruncate_extents
as they are useful for the attribute fork as well - in fact the attr code
already does an equivalent xfs_trans_log_inode call just after calling
xfs_itruncate_extents.  The conditional size updates are a mess, and there
was no reason to do them in two places anyway, as the first one was
conditional on the inode having extents - but without extents we
xfs_itruncate_extents would be a no-op and the placement wouldn't matter
anyway.  Instead move the size assignments and the asserts that make sense
to the callers that want it.

As a side effect of this clean up xfs_setattr_size by introducing variables
for the old and new inode size, and moving the size updates into a common
place.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-13 12:11:45 -06:00
Ian Kent 8638094e95 autofs4 - fix deal with autofs4_write races
I don't know how I missed this obvious mistake when I
reviewed Als' patches, sorry.

[ Quoting Al:

	Grr...  Note to self: do git status *and* git stash show -p
	before git push.  Nothing like "WTF? I'd fixed that braino"
	feeling ;-/

  Al sent the same patch - it got broken in commit d668dc56631d:
  "autofs4: deal with autofs4_write/autofs4_write races". ]

Reported-and-tested-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-13 08:30:49 -08:00
Artem Bityutskiy 515315a123 UBIFS: fix key printing
Before commit 56e46742e8 we have had locking
around all printing macros and we could use static buffers for creating
key strings and printing them. However, now we do not have that locking and
we cannot use static buffers. This commit removes the old DBGKEY() macros
and introduces few new helper macros for printing debugging messages plus
a key at the end. Thankfully, all the messages are already structures in
a way that the key is printed in the end.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2012-01-13 12:50:42 +02:00
Artem Bityutskiy beba006074 UBIFS: use snprintf instead of sprintf when printing keys
Switch to 'snprintf()' which is more secure and reliable. This is also a
preparation to the subsequent key printing fixes.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2012-01-13 12:46:21 +02:00
Linus Torvalds 099469502f Merge branch 'akpm' (aka "Andrew's patch-bomb, take two")
Andrew explains:

 - various misc stuff

 - Most of the rest of MM: memcg, threaded hugepages, others.

 - cpumask

 - kexec

 - kdump

 - some direct-io performance tweaking

 - radix-tree optimisations

 - new selftests code

   A note on this: often people will develop a new userspace-visible
   feature and will develop userspace code to exercise/test that
   feature.  Then they merge the patch and the selftest code dies.
   Sometimes we paste it into the changelog.  Sometimes the code gets
   thrown into Documentation/(!).

   This saddens me.  So this patch creates a bare-bones framework which
   will henceforth allow me to ask people to include their test apps in
   the kernel tree so we can keep them alive.  Then when people enhance
   or fix the feature, I can ask them to update the test app too.

   The infrastruture is terribly trivial at present - let's see how it
   evolves.

 - checkpoint/restart feature work.

   A note on this: this is a project by various mad Russians to perform
   c/r mainly from userspace, with various oddball helper code added
   into the kernel where the need is demonstrated.

   So rather than some large central lump of code, what we have is
   little bits and pieces popping up in various places which either
   expose something new or which permit something which is normally
   kernel-private to be modified.

   The overall project is an ongoing thing.  I've judged that the size
   and scope of the thing means that we're more likely to be successful
   with it if we integrate the support into mainline piecemeal rather
   than allowing it all to develop out-of-tree.

   However I'm less confident than the developers that it will all
   eventually work! So what I'm asking them to do is to wrap each piece
   of new code inside CONFIG_CHECKPOINT_RESTORE.  So if it all
   eventually comes to tears and the project as a whole fails, it should
   be a simple matter to go through and delete all trace of it.

This lot pretty much wraps up the -rc1 merge for me.

* akpm: (96 commits)
  unlzo: fix input buffer free
  ramoops: update parameters only after successful init
  ramoops: fix use of rounddown_pow_of_two()
  c/r: prctl: add PR_SET_MM codes to set up mm_struct entries
  c/r: procfs: add start_data, end_data, start_brk members to /proc/$pid/stat v4
  c/r: introduce CHECKPOINT_RESTORE symbol
  selftests: new x86 breakpoints selftest
  selftests: new very basic kernel selftests directory
  radix_tree: take radix_tree_path off stack
  radix_tree: remove radix_tree_indirect_to_ptr()
  dio: optimize cache misses in the submission path
  vfs: cache request_queue in struct block_device
  fs/direct-io.c: calculate fs_count correctly in get_more_blocks()
  drivers/parport/parport_pc.c: fix warnings
  panic: don't print redundant backtraces on oops
  sysctl: add the kernel.ns_last_pid control
  kdump: add udev events for memory online/offline
  include/linux/crash_dump.h needs elf.h
  kdump: fix crash_kexec()/smp_send_stop() race in panic()
  kdump: crashk_res init check for /sys/kernel/kexec_crash_size
  ...
2012-01-12 20:42:54 -08:00
Cyrill Gorcunov b3f7f573a2 c/r: procfs: add start_data, end_data, start_brk members to /proc/$pid/stat v4
The mm->start_code/end_code, mm->start_data/end_data, mm->start_brk are
involved into calculation of program text/data segment sizes (which might
be seen in /proc/<pid>/statm) and into brk() call final address.

For restore we need to know all these values.  While
mm->start_code/end_code already present in /proc/$pid/stat, the rest
members are not, so this patch brings them in.

The restore procedure of these members is addressed in another patch using
prctl().

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Vagin <avagin@openvz.org>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12 20:13:13 -08:00
Andi Kleen 65dd2aa90a dio: optimize cache misses in the submission path
Some investigation of a transaction processing workload showed that a
major consumer of cycles in __blockdev_direct_IO is the cache miss while
accessing the block size.  This is because it has to walk the chain from
block_dev to gendisk to queue.

The block size is needed early on to check alignment and sizes.  It's only
done if the check for the inode block size fails.  But the costly block
device state is unconditionally fetched.

- Reorganize the code to only fetch block dev state when actually
  needed.

Then do a prefetch on the block dev early on in the direct IO path.  This
is worth it, because there is substantial code run before we actually
touch the block dev now.

- I also added some unlikelies to make it clear the compiler that block
  device fetch code is not normally executed.

This gave a small, but measurable improvement on a large database
benchmark (about 0.3%)

[akpm@linux-foundation.org: coding-style fixes]
[sfr@canb.auug.org.au: using prefetch requires including prefetch.h]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12 20:13:12 -08:00
Andi Kleen 87192a2a49 vfs: cache request_queue in struct block_device
This makes it possible to get from the inode to the request_queue with one
less cache miss.  Used in followon optimization.

The livetime of the pointer is the same as the gendisk.

This assumes that the queue will always stay the same in the gendisk while
it's visible to block_devices.  I think that's safe correct?

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12 20:13:12 -08:00
Tao Ma ae55e1aaa7 fs/direct-io.c: calculate fs_count correctly in get_more_blocks()
In get_more_blocks(), we use dio_count to calcuate fs_count and do some
tricky things to increase fs_count if dio_count isn't aligned.  But
actually it still has some corner cases that can't be coverd.  See the
following example:

	dio_write foo -s 1024 -w 4096

(direct write 4096 bytes at offset 1024).  The same goes if the offset
isn't aligned to fs_blocksize.

In this case, the old calculation counts fs_count to be 1, but actually we
will write into 2 different blocks (if fs_blocksize=4096).  The old code
just works, since it will call get_block twice (and may have to allocate
and create extents twice for filesystems like ext4).  So we'd better call
get_block just once with the proper fs_count.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Christoph Hellwig <hch@lst.de>
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>
2012-01-12 20:13:12 -08:00
Mel Gorman a6bc32b899 mm: compaction: introduce sync-light migration for use by compaction
This patch adds a lightweight sync migrate operation MIGRATE_SYNC_LIGHT
mode that avoids writing back pages to backing storage.  Async compaction
maps to MIGRATE_ASYNC while sync compaction maps to MIGRATE_SYNC_LIGHT.
For other migrate_pages users such as memory hotplug, MIGRATE_SYNC is
used.

This avoids sync compaction stalling for an excessive length of time,
particularly when copying files to a USB stick where there might be a
large number of dirty pages backed by a filesystem that does not support
->writepages.

[aarcange@redhat.com: This patch is heavily based on Andrea's work]
[akpm@linux-foundation.org: fix fs/nfs/write.c build]
[akpm@linux-foundation.org: fix fs/btrfs/disk-io.c build]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andy Isaacson <adi@hexapodia.org>
Cc: Nai Xia <nai.xia@gmail.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12 20:13:09 -08:00
Mel Gorman b969c4ab9f mm: compaction: determine if dirty pages can be migrated without blocking within ->migratepage
Asynchronous compaction is used when allocating transparent hugepages to
avoid blocking for long periods of time.  Due to reports of stalling,
there was a debate on disabling synchronous compaction but this severely
impacted allocation success rates.  Part of the reason was that many dirty
pages are skipped in asynchronous compaction by the following check;

	if (PageDirty(page) && !sync &&
		mapping->a_ops->migratepage != migrate_page)
			rc = -EBUSY;

This skips over all mapping aops using buffer_migrate_page() even though
it is possible to migrate some of these pages without blocking.  This
patch updates the ->migratepage callback with a "sync" parameter.  It is
the responsibility of the callback to fail gracefully if migration would
block.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andy Isaacson <adi@hexapodia.org>
Cc: Nai Xia <nai.xia@gmail.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12 20:13:09 -08:00
Jason Baron 28d82dc1c4 epoll: limit paths
The current epoll code can be tickled to run basically indefinitely in
both loop detection path check (on ep_insert()), and in the wakeup paths.
The programs that tickle this behavior set up deeply linked networks of
epoll file descriptors that cause the epoll algorithms to traverse them
indefinitely.  A couple of these sample programs have been previously
posted in this thread: https://lkml.org/lkml/2011/2/25/297.

To fix the loop detection path check algorithms, I simply keep track of
the epoll nodes that have been already visited.  Thus, the loop detection
becomes proportional to the number of epoll file descriptor and links.
This dramatically decreases the run-time of the loop check algorithm.  In
one diabolical case I tried it reduced the run-time from 15 mintues (all
in kernel time) to .3 seconds.

Fixing the wakeup paths could be done at wakeup time in a similar manner
by keeping track of nodes that have already been visited, but the
complexity is harder, since there can be multiple wakeups on different
cpus...Thus, I've opted to limit the number of possible wakeup paths when
the paths are created.

This is accomplished, by noting that the end file descriptor points that
are found during the loop detection pass (from the newly added link), are
actually the sources for wakeup events.  I keep a list of these file
descriptors and limit the number and length of these paths that emanate
from these 'source file descriptors'.  In the current implemetation I
allow 1000 paths of length 1, 500 of length 2, 100 of length 3, 50 of
length 4 and 10 of length 5.  Note that it is sufficient to check the
'source file descriptors' reachable from the newly added link, since no
other 'source file descriptors' will have newly added links.  This allows
us to check only the wakeup paths that may have gotten too long, and not
re-check all possible wakeup paths on the system.

In terms of the path limit selection, I think its first worth noting that
the most common case for epoll, is probably the model where you have 1
epoll file descriptor that is monitoring n number of 'source file
descriptors'.  In this case, each 'source file descriptor' has a 1 path of
length 1.  Thus, I believe that the limits I'm proposing are quite
reasonable and in fact may be too generous.  Thus, I'm hoping that the
proposed limits will not prevent any workloads that currently work to
fail.

In terms of locking, I have extended the use of the 'epmutex' to all
epoll_ctl add and remove operations.  Currently its only used in a subset
of the add paths.  I need to hold the epmutex, so that we can correctly
traverse a coherent graph, to check the number of paths.  I believe that
this additional locking is probably ok, since its in the setup/teardown
paths, and doesn't affect the running paths, but it certainly is going to
add some extra overhead.  Also, worth noting is that the epmuex was
recently added to the ep_ctl add operations in the initial path loop
detection code using the argument that it was not on a critical path.

Another thing to note here, is the length of epoll chains that is allowed.
Currently, eventpoll.c defines:

/* Maximum number of nesting allowed inside epoll sets */
#define EP_MAX_NESTS 4

This basically means that I am limited to a graph depth of 5 (EP_MAX_NESTS
+ 1).  However, this limit is currently only enforced during the loop
check detection code, and only when the epoll file descriptors are added
in a certain order.  Thus, this limit is currently easily bypassed.  The
newly added check for wakeup paths, stricly limits the wakeup paths to a
length of 5, regardless of the order in which ep's are linked together.
Thus, a side-effect of the new code is a more consistent enforcement of
the graph depth.

Thus far, I've tested this, using the sample programs previously
mentioned, which now either return quickly or return -EINVAL.  I've also
testing using the piptest.c epoll tester, which showed no difference in
performance.  I've also created a number of different epoll networks and
tested that they behave as expectded.

I believe this solves the original diabolical test cases, while still
preserving the sane epoll nesting.

Signed-off-by: Jason Baron <jbaron@redhat.com>
Cc: Nelson Elhage <nelhage@ksplice.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12 20:13:04 -08:00