This is picking up on Felix's repost of Dave's patch to implement a
.dirty_inode method.  We really need this notification because
the VFS keeps writing directly into the inode structure instead
of going through methods to update this state.  In addition to
the long-known atime issue we now also have a caller in VM code
that updates c/mtime that way for shared writeable mmaps.  And
I found another one that no one has noticed in practice in the FIFO
code.

So implement ->dirty_inode to set i_update_core whenever the
inode gets externally dirtied, and switch the c/mtime handling to
the same scheme we already use for atime (always picking up
the value from the Linux inode).

Note that this patch also removes the xfs_synchronize_atime call
in xfs_reclaim it was superflous as we already synchronize the time
when writing the inode via the log (xfs_inode_item_format) or the
normal buffers (xfs_iflush_int).

In addition also remove the I_CLEAR check before copying the Linux
timestamps - now that we always have the Linux inode available
we can always use the timestamps in it.

Also switch to just using file_update_time for regular reads/writes -
that will get us all optimization done to it for free and make
sure we notice early when it breaks.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NAlex Elder <aelder@sgi.com>

fix the following 'make includecheck' warning:

  fs/xfs/linux-2.6/xfs_iops.c: xfs_acl.h is included more than once.
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NAlex Elder <aelder@sgi.com>

create_proc_read_entry() is getting deprecated.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NAlex Elder <aelder@sgi.com>

We added the ENOSPC handling patch in xfs_create just after it got mered
with xfs_mkdir.  Change the log reservation to the variable for either
the create or mkdir value so it does the right thing if get here for creating
a directory.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

- As ima_counts_put() may be called after the inode has been freed,
verify that the inode is not NULL, before dereferencing it.

- Maintain the IMA file counters in may_open() properly, decrementing
any counter increments on subsequent errors.
Reported-by: NCiprian Docan <docan@eden.rutgers.edu>
Reported-by: NJ.R. Okajima <hooanon05@yahoo.co.jp>
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com
Signed-off-by: NJames Morris <jmorris@namei.org>

In ext2_rename(), dir_page is acquired through ext2_dotdot().  It is
then released through ext2_set_link() but only if old_dir != new_dir.
Failing that, the pkmap reference count is never decremented and the
page remains pinned forever.  Repeat that a couple times with highmem
pages and all pkmap slots get exhausted, and every further kmap() calls
end up stalling on the pkmap_map_wait queue at which point the whole
system comes to a halt.
Signed-off-by: NNicolas Pitre <nico@marvell.com>
Acked-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Tom Horsley reports that his debugger hangs when it tries to read
/proc/pid_of_tracee/maps, this happens since

	"mm_for_maps: take ->cred_guard_mutex to fix the race with exec"
	04b836cbf19e885f8366bccb2e4b0474346c02d

commit in 2.6.31.

But the root of the problem lies in the fact that do_execve() path calls
tracehook_report_exec() which can stop if the tracer sets PT_TRACE_EXEC.

The tracee must not sleep in TASK_TRACED holding this mutex.  Even if we
remove ->cred_guard_mutex from mm_for_maps() and proc_pid_attr_write(),
another task doing PTRACE_ATTACH should not hang until it is killed or the
tracee resumes.

With this patch do_execve() does not use ->cred_guard_mutex directly and
we do not hold it throughout, instead:

	- introduce prepare_bprm_creds() helper, it locks the mutex
	  and calls prepare_exec_creds() to initialize bprm->cred.

	- install_exec_creds() drops the mutex after commit_creds(),
	  and thus before tracehook_report_exec()->ptrace_stop().

	  or, if exec fails,

	  free_bprm() drops this mutex when bprm->cred != NULL which
	  indicates install_exec_creds() was not called.
Reported-by: NTom Horsley <tom.horsley@att.net>
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Bug introduced by mainline commit e7432675
The bug causes ocfs2_write_begin_nolock() to oops when len=0.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Cc: stable@kernel.org
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

The function jffs2_nor_wbuf_flash_setup() doesn't allocate the verify buffer
if CONFIG_JFFS2_FS_WBUF_VERIFY is defined, so causing a kernel panic when
that macro is enabled and the verify function is called. Similarly the
jffs2_nor_wbuf_flash_cleanup() must free the buffer if
CONFIG_JFFS2_FS_WBUF_VERIFY is enabled.
The following patch fixes the problem.
The following patch applies to 2.6.30 kernel.
Signed-off-by: NMassimo Cirillo <maxcir@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org

If you enable group or project quotas on an XFS file system, then the
mount table presented through /proc/self/mounts erroneously shows
that both options are in effect for the file system.  The root of
the problem is some bad logic in the xfs_showargs() function, which
is used to format the file system type-specific options in effect
for a file system.

The problem originated in this GIT commit:
    Move platform specific mount option parse out of core XFS code
    Date: 11/22/07
    Author: Dave Chinner
    SHA1 ID: a67d7c5f

For XFS quotas, project and group quota management are mutually
exclusive--only one can be in effect at a time.  There are two
parts to managing quotas:  aggregating usage information; and
enforcing limits.  It is possible to have a quota in effect
(aggregating usage) but not enforced.

These features are recorded on an XFS mount point using these flags:
    XFS_PQUOTA_ACCT - Project quotas are aggregated
    XFS_GQUOTA_ACCT - Group quotas are aggregated
    XFS_OQUOTA_ENFD - Project/group quotas are enforced

The code in error is in fs/xfs/linux-2.6/xfs_super.c:

        if (mp->m_qflags & (XFS_PQUOTA_ACCT|XFS_OQUOTA_ENFD))
                seq_puts(m, "," MNTOPT_PRJQUOTA);
        else if (mp->m_qflags & XFS_PQUOTA_ACCT)
                seq_puts(m, "," MNTOPT_PQUOTANOENF);

        if (mp->m_qflags & (XFS_GQUOTA_ACCT|XFS_OQUOTA_ENFD))
                seq_puts(m, "," MNTOPT_GRPQUOTA);
        else if (mp->m_qflags & XFS_GQUOTA_ACCT)
                seq_puts(m, "," MNTOPT_GQUOTANOENF);

The problem is that XFS_OQUOTA_ENFD will be set in mp->m_qflags
if either group or project quotas are enforced, and as a result
both MNTOPT_PRJQUOTA and MNTOPT_GRPQUOTA will be shown as mount
options.
Signed-off-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>

xfs_inobt_lookup is also used in xfs_itable.c, remove the STATIC modifier
from it's declaration to fix non-debug builds.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

Fix a small typo in the compat ioctl handler that cause the swapext
compat handler to never be called.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NTorsten Kaiser <just.for.lkml@googlemail.com>
Tested-by: NTorsten Kaiser <just.for.lkml@googlemail.com>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

Fix a small typo in the compat ioctl handler that cause the swapext
compat handler to never be called.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NTorsten Kaiser <just.for.lkml@googlemail.com>
Tested-by: NTorsten Kaiser <just.for.lkml@googlemail.com>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

xfs_trans_iget is a wrapper for xfs_iget that adds the inode to the
transaction after it is read.  Except when the inode already is in the
inode cache, in which case it returns the existing locked inode with
increment lock recursion counts.

Now, no one in the tree every decrements these lock recursion counts,
so any user of this gets a potential double unlock when both the original
owner of the inode and the xfs_trans_iget caller unlock it.  When looking
back in a git bisect in the historic XFS tree there was only one place
that decremented these counts, xfs_trans_iput.  Introduced in commit
ca25df7a840f426eb566d52667b6950b92bb84b5 by Adam Sweeney in 1993,
and removed in commit 19f899a3ab155ff6a49c0c79b06f2f61059afaf3 by
Steve Lord in 2003.  And as long as it didn't slip through git bisects
cracks never actually used in that time frame.

A quick audit of the callers of xfs_trans_iget shows that no caller
really relies on this behaviour fortunately - xfs_ialloc allows this
inode from disk so it must not be there before, and all the RT allocator
routines only every add each RT bitmap inode once.

In addition to removing lots of code and reducing the size of the inode
item this patch also avoids the double inode cache lookup in each
create/mkdir/mknod transaction.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

The guarantees for O_SYNC are exactly the same as the ones we need to
make for an fsync call (and given that Linux O_SYNC is O_DSYNC the
equivalent is fdadatasync, but we treat both the same in XFS), except
with a range data writeout.  Jan Kara has started unifying these two
path for filesystems using the generic helpers, and I've started to
look at XFS.

The actual transaction commited by xfs_fsync and xfs_write_sync_logforce
has a different transaction number, but actually is exactly the same.
We'll only use the fsync transaction going forward.  One major difference
is that xfs_write_sync_logforce never issues a cache flush unless we
commit a transaction causing that as a side-effect, which is an obvious
bug in the O_SYNC handling.  Second all the locking and i_update_size
vs i_update_core changes from 978b7237
never made it to xfs_write_sync_logforce, so we add them back.

To make xfs_fsync easily usable from the O_SYNC path, the filemap_fdatawait
call is moved up to xfs_file_fsync, so that we don't wait on the whole
file after we already waited for our portion in xfs_write.

We'll also use a plain call to filemap_write_and_wait_range instead
of the previous sync_page_rang which did it in two steps including
an half-hearted inode write out that doesn't help us.

Once we're done with this also remove the now useless i_update_size
tracking.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

Don't search too far - abort if it is outside a certain radius and simply do
a linear search for the first free inode.  In AGs with a million inodes this
can speed up allocation speed by 3-4x.

[hch: ported to the new xfs_ialloc.c world order]
Signed-off-by: NDave Chinner <dgc@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

Currenly we have a xfs_inobt_lookup* variant for each comparism direction,
and all these get all three fields of the inobt records passed, while the
common case is just looking for the inode number and we have only marginally
more callers than xfs_inobt_lookup* variants.

So opencode a direct call to xfs_btree_lookup for the single case where we
need all fields, and replace xfs_inobt_lookup* with a xfs_inobt_looku that
just takes the inode number and the direction for all other callers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

Clarify the control flow in xfs_dialloc.  Factor out a helper to go to the
next node from the current one and improve the control flow by expanding
composite if statements and using gotos.

The xfs_ialloc_next_rec helper is borrowed from Dave Chinners dynamic
allocation policy patches.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

Factor out a common helper from repeated debug checks in xfs_dialloc and
xfs_difree.

[hch: split out from Dave's dynamic allocation policy patches]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

Both callers of xfs_inobt_update have the record in form of a
xfs_inobt_rec_incore_t, so just pass a pointer to it instead of the
individual variables.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

Most callers of xfs_inobt_get_rec need to fill a xfs_inobt_rec_incore_t, and
those who don't yet are fine with a xfs_inobt_rec_incore_t, instead of the
three individual variables, too.  So just change xfs_inobt_get_rec to write
the output into a xfs_inobt_rec_incore_t directly.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

Factor out code to initialize new inode clusters into a function of it's own.
This keeps xfs_ialloc_ag_alloc smaller and better structured and enables a
future inode cluster initialization transaction.  Also initialize the agno
variable earlier in xfs_ialloc_ag_alloc to avoid repeated byte swaps.

[hch:  The original patch is from Dave from his unpublished inode create
 transaction patch series, with some modifcations by me to apply stand-alone]
Signed-off-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

In the recent change by Al Viro that changes verious subsystems
to use "struct path" one case was missed in the autofs4 module
which causes mounts to no longer expire.
Signed-off-by: NIan Kent <raven@themaw.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

bp was tested for NULL a few lines before, followed by a return, and there
is no intervening modification of its value.

A simplified version of the semantic match that finds this problem is as
follows: (http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
local idexpression x;
expression E;
position p1,p2;
@@

if (x == NULL || ...) { ... when forall
   return ...; }
... when != \(x=E\|x--\|x++\|--x\|++x\|x-=E\|x+=E\|x|=E\|x&=E\|&x\)
(
*x == NULL
|
*x != NULL
)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Acked-by: NFelix Blyakher <felixb@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

Commit a19d9f88 removed the
ino64 option but left the XFS_INO64_OFFSET define it used
in place - just remove it.
Signed-off-by: NEric Sandeen <sandeen@sandeen.net>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

CONFIG_XFS_DEBUG builds still need xfs_read_agf to be
non-static, oops.
Signed-off-by: NEric Sandeen <sandeen@sandeen.net>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

A lot more functions could be made static, but they need
forward declarations; this does some easy ones, and also
found a few unused functions in the process.
Signed-off-by: NEric Sandeen <sandeen@sandeen.net>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

This will fix the following preempt count underflow reported from
users with the title "[NILFS users] segctord problem" (Message-ID:
<949415.6494.qm@web58808.mail.re1.yahoo.com> and Message-ID:
<debc30fc0908270825v747c1734xa59126623cfd5b05@mail.gmail.com>):

 WARNING: at kernel/sched.c:4890 sub_preempt_count+0x95/0xa0()
 Hardware name: HP Compaq 6530b (KR980UT#ABC)
 Modules linked in: bridge stp llc bnep rfcomm l2cap xfs exportfs nilfs2 cowloop loop vboxnetadp vboxnetflt vboxdrv btusb bluetooth uvcvideo videodev v4l1_compat v4l2_compat_ioctl32 arc4 snd_hda_codec_analog ecb iwlagn iwlcore rfkill lib80211 mac80211 snd_hda_intel snd_hda_codec ehci_hcd uhci_hcd usbcore snd_hwdep snd_pcm tg3 cfg80211 psmouse snd_timer joydev libphy ohci1394 snd_page_alloc hp_accel lis3lv02d ieee1394 led_class i915 drm i2c_algo_bit video backlight output i2c_core dm_crypt dm_mod
 Pid: 4197, comm: segctord Not tainted 2.6.30-gentoo-r4-64 #7
 Call Trace:
  [<ffffffff8023fa05>] ? sub_preempt_count+0x95/0xa0
  [<ffffffff802470f8>] warn_slowpath_common+0x78/0xd0
  [<ffffffff8024715f>] warn_slowpath_null+0xf/0x20
  [<ffffffff8023fa05>] sub_preempt_count+0x95/0xa0
  [<ffffffffa04ce4db>] nilfs_btnode_prepare_change_key+0x11b/0x190 [nilfs2]
  [<ffffffffa04d01ad>] nilfs_btree_assign_p+0x19d/0x1e0 [nilfs2]
  [<ffffffffa04d10ad>] nilfs_btree_assign+0xbd/0x130 [nilfs2]
  [<ffffffffa04cead7>] nilfs_bmap_assign+0x47/0x70 [nilfs2]
  [<ffffffffa04d9bc6>] nilfs_segctor_do_construct+0x956/0x20f0 [nilfs2]
  [<ffffffff805ac8e2>] ? _spin_unlock_irqrestore+0x12/0x40
  [<ffffffff803c06e0>] ? __up_write+0xe0/0x150
  [<ffffffff80262959>] ? up_write+0x9/0x10
  [<ffffffffa04ce9f3>] ? nilfs_bmap_test_and_clear_dirty+0x43/0x60 [nilfs2]
  [<ffffffffa04cd627>] ? nilfs_mdt_fetch_dirty+0x27/0x60 [nilfs2]
  [<ffffffffa04db5fc>] nilfs_segctor_construct+0x8c/0xd0 [nilfs2]
  [<ffffffffa04dc3dc>] nilfs_segctor_thread+0x15c/0x3a0 [nilfs2]
  [<ffffffffa04dbe20>] ? nilfs_construction_timeout+0x0/0x10 [nilfs2]
  [<ffffffff80252633>] ? add_timer+0x13/0x20
  [<ffffffff802370da>] ? __wake_up_common+0x5a/0x90
  [<ffffffff8025e960>] ? autoremove_wake_function+0x0/0x40
  [<ffffffffa04dc280>] ? nilfs_segctor_thread+0x0/0x3a0 [nilfs2]
  [<ffffffffa04dc280>] ? nilfs_segctor_thread+0x0/0x3a0 [nilfs2]
  [<ffffffff8025e556>] kthread+0x56/0x90
  [<ffffffff8020cdea>] child_rip+0xa/0x20
  [<ffffffff8025e500>] ? kthread+0x0/0x90
  [<ffffffff8020cde0>] ? child_rip+0x0/0x20

This problem was caused due to a missing radix_tree_preload() call in
the retry path of nilfs_btnode_prepare_change_key() function.
Reported-by: NEric A <eric225125@yahoo.com>
Reported-by: NJerome Poulin <jeromepoulin@gmail.com>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: NJerome Poulin <jeromepoulin@gmail.com>
Cc: stable@kernel.org

Seperating the addition and update of marks in inotify resulted in a
regression in that inotify never gets events.  The inotify group mask is
always 0.  This mask should be updated any time a new mark is added.
Signed-off-by: NEric Paris <eparis@redhat.com>

0db501bd introduced a regresion in that it now sends a nul
terminator but the length accounting when checking for space or
reporting to userspace did not take this into account.  This corrects
all of the rounding logic.
Signed-off-by: NEric Paris <eparis@redhat.com>

When an event has no pathname, there's no need to pad it with a null byte and
therefore generate an inotify_event sized block of zeros. This fixes a
regression introduced by commit 0db501bd where
my system wouldn't finish booting because some process was being confused by
this.
Signed-off-by: NBrian Rogers <brian@xyzw.org>
Signed-off-by: NEric Paris <eparis@redhat.com>

In commit a5a0a630, when
ocfs2_attch_dentry_lock fails, we call an extra iput and reset
dentry->d_fsdata to NULL. This resolve a bug, but it isn't
completed and the dentry is still there. When we want to use
it again, ocfs2_dentry_revalidate doesn't catch it and return
true. That make future ocfs2_dentry_lock panic out.
One bug is http://oss.oracle.com/bugzilla/show_bug.cgi?id=1162.

The resolution is to add a check for dentry->d_fsdata in
revalidate process and return false if dentry->d_fsdata is NULL,
so that a new ocfs2_lookup will be called again.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

kAFS crashes when asked to read a symbolic link because page_getlink()
passes a NULL file pointer to read_mapping_page(), but afs_readpage()
expects a file pointer from which to extract a key.

Modify afs_readpage() to request the appropriate key from the calling
process's keyrings if a file struct is not supplied with one attached.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Before the rewrite copy_event_to_user always wrote a terqminating '\0'
byte to user space after the filename.  Since the rewrite that
terminating byte was skipped if your filename is exactly a multiple of
event_size.  Ouch!

So add one byte to name_size before we round up and use clear_user to
set userspace to zero like /dev/zero does instead of copying the
strange nul_inotify_event.  I can't quite convince myself len_to_zero
will never exceed 16 and even if it doesn't clear_user should be more
efficient and a more accurate reflection of what the code is trying to
do.
Signed-off-by: NEric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

The are races around the idr storage of inotify watches.  It's possible
that a watch could be found from sys_inotify_rm_watch() in the idr, but it
could be removed from the idr before that code does it's removal.  Move the
locking and the refcnt'ing so that these have to happen atomically.
Signed-off-by: NEric Paris <eparis@redhat.com>

If an inotify watch is left in the idr when an fsnotify group is destroyed
this will lead to a BUG.  This is not a dangerous situation and really
indicates a programming bug and leak of memory.  This patch changes it to
use a WARN and a printk rather than killing people's boxes.
Signed-off-by: NEric Paris <eparis@redhat.com>

There is nothing known wrong with the inotify watch addition/modification
but this patch seperates the two code paths to make them each easy to
verify as correct.
Signed-off-by: NEric Paris <eparis@redhat.com>

Commit 76db6d95 (nfs41: add session setup
to the state manager) introduces an infinite loop possibility in the NFSv4
state manager. By first checking nfs4_has_session() before clearing the
NFS4CLNT_SESSION_SETUP flag, it allows for a situation where someone sets
that flag, but it never gets cleared, and so the state manager loops.

In fact commit c3fad1b1 (nfs41: add session
reset to state manager) causes this to happen every time we get a network
partition error.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: NDaniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

2.6.30's commit 8a0bdec1 removed
user_shm_lock() calls in hugetlb_file_setup() but left the
user_shm_unlock call in shm_destroy().

In detail:
Assume that can_do_hugetlb_shm() returns true and hence user_shm_lock()
is not called in hugetlb_file_setup(). However, user_shm_unlock() is
called in any case in shm_destroy() and in the following
atomic_dec_and_lock(&up->__count) in free_uid() is executed and if
up->__count gets zero, also cleanup_user_struct() is scheduled.

Note that sched_destroy_user() is empty if CONFIG_USER_SCHED is not set.
However, the ref counter up->__count gets unexpectedly non-positive and
the corresponding structs are freed even though there are live
references to them, resulting in a kernel oops after a lots of
shmget(SHM_HUGETLB)/shmctl(IPC_RMID) cycles and CONFIG_USER_SCHED set.

Hugh changed Stefan's suggested patch: can_do_hugetlb_shm() at the
time of shm_destroy() may give a different answer from at the time
of hugetlb_file_setup().  And fixed newseg()'s no_id error path,
which has missed user_shm_unlock() ever since it came in 2.6.9.
Reported-by: NStefan Huber <shuber2@gmail.com>
Signed-off-by: NHugh Dickins <hugh.dickins@tiscali.co.uk>
Tested-by: NStefan Huber <shuber2@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch makes the error message about changing journaling mode on remount
more descriptive. Some people are going to hit this error now due to commit
bbae8bcc if they configure a kernel to default
to data=writeback mode. The problem happens if they have data=ordered set for
the root filesystem in /etc/fstab but not in the kernel command line (and they
don't use initrd). Their filesystem then gets mounted as data=writeback by
kernel but then their boot fails because init scripts won't be able to remount
the filesystem rw. Better error message will hopefully make it easier for them
to find the error in their setup and bother us less with error reports :).
Signed-off-by: NJan Kara <jack@suse.cz>