This fourth patch of eight in this cleancache series provides the
core hooks in VFS for: initializing cleancache per filesystem;
capturing clean pages reclaimed by page cache; attempting to get
pages from cleancache before filesystem read; and ensuring coherency
between pagecache, disk, and cleancache.  Note that the placement
of these hooks was stable from 2.6.18 to 2.6.38; a minor semantic
change was required due to a patchset in 2.6.39.

All hooks become no-ops if CONFIG_CLEANCACHE is unset, or become
a check of a boolean global if CONFIG_CLEANCACHE is set but no
cleancache "backend" has claimed cleancache_ops.

Details and a FAQ can be found in Documentation/vm/cleancache.txt

[v8: minchan.kim@gmail.com: adapt to new remove_from_page_cache function]
Signed-off-by: NChris Mason <chris.mason@oracle.com>
Signed-off-by: NDan Magenheimer <dan.magenheimer@oracle.com>
Reviewed-by: NJeremy Fitzhardinge <jeremy@goop.org>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik Van Riel <riel@redhat.com>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: Andreas Dilger <adilger@sun.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Nitin Gupta <ngupta@vflare.org>

configfs_readdir() will use the existing inode numbers of inodes in the
dcache, but it makes them up for attribute files that aren't currently
instantiated.  There is a race where a closing attribute file can be
tearing down at the same time as configfs_readdir() is trying to get its
inode number.

We want to get the inode number of open attribute files, because they
should match while instantiated.  We can't lock down the transition
where dentry->d_inode is set to NULL, so we just check for NULL there.
We can, however, ensure that an inode we find isn't iput() in
configfs_d_iput() until after we've accessed it.
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

When configfs is faking mkdir() on its subsystem or default group
objects, it starts by adding a negative dentry.  It then tries to
instantiate the group.  If that should fail, it must clean up after
itself.

I was using d_delete() here, but configfs_attach_group() promises to
return an empty dentry on error.  d_delete() explodes with the entry
dentry.  Let's try d_drop() instead.  The unhashing is what we want for
our dentry.
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

As Metze pointed out, commit 84cdf74e broke mapchars option:

    Commit "cifs: fix unaligned accesses in cifsConvertToUCS"
    (84cdf74e) does multiple steps
    in just one commit (moving the function and changing it without
    testing).

    put_unaligned_le16(temp, &target[j]); is never called for any
    codepoint the goes via the 'default' switch statement. As a result
    we put just zero (or maybe uninitialized) bytes into the target
    buffer.

His proposed patch looks correct, but doesn't apply to the current head
of the tree. This patch should also fix it.

Cc: <stable@kernel.org> # .38.x: 581ade4d: cifs: clean up various nits in unicode routines (try #2)
Reported-by: NStefan Metzmacher <metze@samba.org>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

The is_path_accessible check uses a QPathInfo call, which isn't
supported by ancient win9x era servers. Fall back to an older
SMBQueryInfo call if it fails with the magic error codes.

Cc: stable@kernel.org
Reported-and-Tested-by: NSandro Bonazzola <sandro.bonazzola@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Steps to reproduce the bug:

  - Call FS_IOC_SETLFAGS ioctl with flags=FS_COMPR_FL
  - Call FS_IOC_SETFLAGS ioctl with flags=0
  - Call FS_IOC_GETFLAGS ioctl, and you'll see FS_COMPR_FL is still set!
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

As we've added per file compression/cow support.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

FS_COW_FL and FS_NOCOW_FL were newly introduced to control per file
COW in btrfs, but FS_NOCOW_FL is sufficient.

The fact is we don't have corresponding BTRFS_INODE_COW flag.

COW is default, and FS_NOCOW_FL can be used to switch off COW for
a single file.

If we mount btrfs with nodatacow, a newly created file will be set with
the FS_NOCOW_FL flag. So to turn on COW for it, we can just clear the
FS_NOCOW_FL flag.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

When a btrfs disk is created by mixed data & metadata option, it will have no
pure data or pure metadata space info.

In btrfs's for-linus branch, commit 78b1ea13838039cd88afdd62519b40b344d6c920
(Btrfs: fix OOPS of empty filesystem after balance) initializes space infos at
the very beginning.  The problem is this initialization does not take the mixed
case into account, which will cause btrfs will easily get into ENOSPC in mixed
case.
Signed-off-by: NLiu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

If posix_acl_from_xattr() returns an error code, a negative address is
dereferenced causing an oops; fix by checking for error code first.
Signed-off-by: NDaniel J Blueman <daniel.blueman@gmail.com>
Reviewed-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

It's a hot function, and we're better off not mixing types in the mask
calculations.  The compiler just ends up mixing 16-bit and 32-bit
operations, for no good reason.

So do everything in 'unsigned int' rather than mixing 'unsigned int'
masking with a 'umode_t' (16-bit) mode variable.

This, together with the parent commit (47a150ed: "Cache user_ns in
struct cred") makes acl_permission_check() much nicer.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

During resource migration, if the target node were to die, the thread doing
the migration spins until the target node is not removed from the domain map.
This patch slows the spin by making the thread wait for the recovery to kick in.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

Patch skips mount recovery for hard-ro mounts which otherwise leads to an oops.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Acked-by: NMark Fasheh <mfasheh@suse.com>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

If o2hb finds unexpected values in the heartbeat slot, it prints a message
"ERROR: Device "dm-6": another node is heartbeating in our slot!"

This message could be misleading. This patch adds two more messages to
help users better diagnose the problem.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Acked-by: NMark Fasheh <mfasheh@suse.com>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

We have seen isolated cases (very few, I might add) of o2hb not detecting all
live nodes on startup. One plausible reasoning for it is that other node had
a hb io delay at the same time. The live threshold set at 2 (as low as it can
be) could be increased to ameliorate the situation.

But increasing the threshold directly affects mount time. Currently it takes
around 5 secs to mount a volume in o2cb cluster with local heartbeat. Increasing
the threshold will make mounts even slower. As the issue itself is rare, we have
left things as they are for the local heartbeat mode.

However we can improve the situation for global heartbeat mode as in that mode,
we start the heartbeat much before the mount.

This patch doubles the live threshold for the start of the first region in
global heartbeat mode.

Addresses internal Oracle bug#10635585.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Acked-by: NMark Fasheh <mfasheh@suse.com>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

Patch fixes a bug in the o2dlm protocol negotiation in that it is using
the builtin version rather than the negotiated version during the domain
join. This causes join errors when a node having kernel >= 2.6.37 joins
a cluster with nodes having kernels < 2.6.37.

This only affects the o2cb cluster stack.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Reported-by: NJacek Stepniewski <Jacek.Stepniewski@agora.pl>
Acked-by: NMark Fasheh <mfasheh@suse.com>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

In the case of removing a partial extent record which covers a hole, current
punching-hole logic will try to remove more than the length of whole extent
record, which leads to the failure of following assert(fs/ocfs2/alloc.c):

5507         BUG_ON(cpos < le32_to_cpu(rec->e_cpos) || trunc_range > rec_range);

This patch tries to skip existing hole at the last attempt of removing a partial
extent record, what's more, it also adds some necessary comments for better
understanding of punching-hole codes.
Signed-off-by: NTristan Ye <tristan.ye@oracle.com>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

CLANG found that there is a path that has data_ac uninitialized,
this place
	2917	/* This gets us the dx_root */
	2918	ret = ocfs2_reserve_new_metadata_blocks(osb, 1, &meta_ac);
	2919	if (ret) {

	3
		Taking true branch
	2920	mlog_errno(ret);
	2921	goto out;

	4
		Control jumps to line 3168
	2922	}

Goes to the out: label without data_ac being initialized.

Ciao, Marcus
Signed-Off-By: NMarcus Meissner <meissner@suse.de>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

Currently, writebacks may end up recursing back into the filesystem due to
GFP_KERNEL direct reclaims in the pnfs subsystem.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Prevents an infinite loop as list was never emptied.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Free the slot and resend the RPC with new session <slot#,seq#>.

For nfs4_async_handle_error, return -EAGAIN and set the task->tk_status to 0
to restart the async rpc in the rpc_restart_call_prepare state which resets
the slot.

For nfs4_handle_exception, retrying a call that uses nfs4_call_sync will
reset the slot via nfs41_call_sync_prepare.

For open/close/lock/locku/delegreturn/layoutcommit/unlink/rename/write
cachethis is true, so these operations will not trigger an
NFS4ERR_RETRY_UNCACHED_REP.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We increments i_wrbuffer_ref when taking the Fb cap. This breaks
the dirty page accounting and causes looping in
__ceph_do_pending_vmtruncate, and ceph client hangs.

This bug can be reproduced occasionally by running blogbench.

Add a new field i_wb_ref to inode and dedicate it to Fb reference
counting.
Signed-off-by: NHenry C Chang <henry.cy.chang@gmail.com>
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NHenry C Chang <henry.cy.chang@gmail.com>
Signed-off-by: NSage Weil <sage@newdream.net>

The mds session, s, could be freed during ceph_put_mds_session.
Move dout before ceph_put_mds_session.
Signed-off-by: NHenry C Chang <henry.cy.chang@gmail.com>
Signed-off-by: NSage Weil <sage@newdream.net>

Some cases (e.g. ecryptfs) can call ->dentry_revalidate with NULL
nameidata.

https://bugzilla.kernel.org/show_bug.cgi?id=34732

Tyler Hicks pointed out that this bug was introduced by commit
e7c0a167 "fuse: make fuse_dentry_revalidate() RCU aware"
Reported-by: NWitold Baryluk <baryluk@smp.if.uj.edu.pl>
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>

After having applied commit 9954e7af ("nilfs2: add free
entries count only if clear bit operation succeeded"), a free routine
of nilfs came to fall into an infinite loop, outputting the same
message endlessly:

 nilfs_palloc_freev: entry number 29497 already freed
 nilfs_palloc_freev: entry number 29497 already freed
 nilfs_palloc_freev: entry number 29497 already freed
 nilfs_palloc_freev: entry number 29497 already freed
 nilfs_palloc_freev: entry number 29497 already freed ...

That patch broke the routine so that a loop counter is never updated
in an abnormal state.  This fixes the regression.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

The recent conversion of the xfsaild functionality to a work queue
introduced a hard-to-hit log space grant hang. One is caused by a
race condition in determining whether there is a psh in progress or
not.

The XFS_AIL_PUSHING_BIT is used to determine whether a push is
currently in progress.  When the AIL push work completes, it checked
whether the target changed and cleared the PUSHING bit to allow a
new push to be requeued. The race condition is as follows:

	Thread 1		push work

	smp_wmb()
				smp_rmb()
				check ailp->xa_target unchanged
	update ailp->xa_target
	test/set PUSHING bit
	does not queue
				clear PUSHING bit
				does not requeue

Now that the push target is updated, new attempts to push the AIL
will not trigger as the push target will be the same, and hence
despite trying to push the AIL we won't ever wake it again.

The fix is to ensure that the AIL push work clears the PUSHING bit
before it checks if the target is unchanged.

As a result, both push triggers operate on the same test/set bit
criteria, so even if we race in the push work and miss the target
update, the thread requesting the push will still set the PUSHING
bit and queue the push work to occur. For safety sake, the same
queue check is done if the push work detects the target change,
though only one of the two will will queue new work due to the use
of test_and_set_bit() checks.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>

(cherry picked from commit e4d3c4a4)

The recent conversion of the xfsaild functionality to a work queue
introduced a hard-to-hit log space grant hang. One of the problems
noticed was that updates of the push target are not 32 bit safe as
the target is a 64 bit value.

We cannot copy a 64 bit LSN without the possibility of corrupting
the result when racing with another updating thread. We have
function to do this update safely without needing to care about
32/64 bit issues - xfs_trans_ail_copy_lsn() - so use that when
updating the AIL push target.

Also move the reading of the target in the push work inside the AIL
lock, and use XFS_LSN_CMP() for the unlocked comparison during work
termination to close read holes as well.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>

(cherry picked from commit fd5670f2)

The recent conversion of the xfsaild functionality to a work queue
introduced a hard-to-hit log space grant hang. One of the problems
discovered is a target mismatch between the item pushing loop and
the target itself.

The push trigger checks for the target increasing (i.e. new target >
current) while the push loop only pushes items that have a LSN <
current. As a result, we can get the situation where the push target
is X, the items at the tail of the AIL have LSN X and they don't get
pushed. The push work then completes thinking it is done, and cannot
be restarted until the push target increases to >= X + 1. If the
push target then never increases (because the tail is not moving),
then we never run the push work again and we stall.

Fix it by making sure log items with a LSN that matches the target
exactly are pushed during the loop.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>

(cherry picked from commit cb64026b)

The recent conversion of the xfsaild functionality to a work queue
introduced a hard-to-hit log space grant hang. The main cause is a
regression where a work exit path fails to clear the PUSHING state
and recheck the target correctly.

Make both exit paths do the same PUSHING bit clearing and target
checking when the "no more work to be done" condition is hit.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>

(cherry picked from commit ea35a200)

On a 32 bit highmem PowerPC machine, the XFS inode cache was growing
without bound and exhausting low memory causing the OOM killer to be
triggered. After some effort, the problem was reproduced on a 32 bit
x86 highmem machine.

The problem is that the per-ag inode reclaim index cursor was not
getting reset to the start of the AG if the radix tree tag lookup
found no more reclaimable inodes. Hence every further reclaim
attempt started at the same index beyond where any reclaimable
inodes lay, and no further background reclaim ever occurred from the
AG.

Without background inode reclaim the VM driven cache shrinker
simply cannot keep up with cache growth, and OOM is the result.

While the change that exposed the problem was the conversion of the
inode reclaim to use work queues for background reclaim, it was not
the cause of the bug. The bug was introduced when the cursor code
was added, just waiting for some weird configuration to strike....
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Tested-By: NChristian Kujau <lists@nerdbynature.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>

(cherry picked from commit b2232219)

Linux kernel excludes guard page when performing mlock on a VMA with
down-growing stack. However, some architectures have up-growing stack
and locking the guard page should be excluded in this case too.

This patch fixes lvm2 on PA-RISC (and possibly other architectures with
up-growing stack). lvm2 calculates number of used pages when locking and
when unlocking and reports an internal error if the numbers mismatch.

[ Patch changed fairly extensively to also fix /proc/<pid>/maps for the
  grows-up case, and to move things around a bit to clean it all up and
  share the infrstructure with the /proc bits.

  Tested on ia64 that has both grow-up and grow-down segments  - Linus ]
Signed-off-by: NMikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Tested-by: NTony Luck <tony.luck@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove unused variable
Signed-off-by: NMikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move declaration up, so that there are no out-of-scope pointers
Reported-by: NJesper Juhl <jj@chaosbits.net>
Signed-off-by: NMikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix some unaligned accesses
Signed-off-by: NMikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix endianity. Make hpfs work on big-endian machines.
Signed-off-by: NMikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Implement fsync for hpfs.
Signed-off-by: NMikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix a bug that filesystem was not marked dirty when remounting it
Signed-off-by: NMikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Restrict uid and gid to 16-bit values.

HPFS stores only 2 bytes in the EAs.
Signed-off-by: NMikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When marking or clearing the dirty bit, sync the filesystem
Signed-off-by: NMikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>