put_files_struct() and close_files() do rcu_read_lock() to make
rcu_dereference_check_fdtable() happy.

This looks a bit ugly, files_fdtable() just reads the pointer,
we can simply use rcu_dereference_raw() to avoid the warning.

The patch also changes close_files() to return fdt, this avoids
another rcu_read_lock()/files_fdtable() in put_files_struct().

I think close_files() needs more cleanups:

	- we do not need xchg() exactly because we are the last
	  user of this files_struct

	- "if (file)" should be turned into WARN_ON(!file)
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

rcu_dereference_check_fdtable() looks very wrong,

1. rcu_my_thread_group_empty() was added by 844b9a87 "vfs: fix
   RCU-lockdep false positive due to /proc" but it doesn't really
   fix the problem. A CLONE_THREAD (without CLONE_FILES) task can
   hit the same race with get_files_struct().

   And otoh rcu_my_thread_group_empty() can suppress the correct
   warning if the caller is the CLONE_FILES (without CLONE_THREAD)
   task.

2. files->count == 1 check is not really right too. Even if this
   files_struct is not shared it is not safe to access it lockless
   unless the caller is the owner.

   Otoh, this check is sub-optimal. files->count == 0 always means
   it is safe to use it lockless even if files != current->files,
   but put_files_struct() has to take rcu_read_lock(). See the next
   patch.

This patch removes the buggy checks and turns fcheck_files() into
__fcheck_files() which uses rcu_dereference_raw(), the "unshared"
callers, fget_light() and fget_raw_light(), can use it to avoid
the warning from RCU-lockdep.

fcheck_files() is trivially reimplemented as rcu_lockdep_assert()
plus __fcheck_files().
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

it's never called with NULL argument...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

kill pointless method instances and don't bother with ->owner - it's
ignored for procfs files anyway, make use of remove_proc_subtree() for
removal, get rid of cell->proc_dir.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

pass owner explicitly to __register_nls(), make register_nls() a macro passing
THIS_MODULE as the owner argument to __register_nls().
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

* don't assume that ->dest_count won't change between copy_from_user()
and memdup_user()
* use fdget instead of fget
* don't bother comparing superblocks when we'd already compared vfsmounts
* get rid of excessive goto
* use file_inode() instead of open-coding the sucker
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

* pass on-disk superblock to qnx4_chkroot() explicitly
* don't leave stale (and unused) pointers in qnx4_super_block
* free stuff in ->kill_sb(); ->put_super() becomes empty and dies
* simplify failure exits
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

simplifies failure exits in ->mount()...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

failure exits are simpler that way
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... and return saner errors from ->mount(), while we are at it
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

don't bother open-coding it...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

If ecryptfs_readlink_lower() fails, buf remains an uninitialized
pointer and passing it nd_set_link() won't do anything good.

Fixed by switching ecryptfs_readlink_lower() to saner API - make it
return buf or ERR_PTR(...) and update callers.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

There is a bug in the function nilfs_segctor_collect, which results in
active data being written to a segment, that is marked as clean.  It is
possible, that this segment is selected for a later segment
construction, whereby the old data is overwritten.

The problem shows itself with the following kernel log message:

  nilfs_sufile_do_cancel_free: segment 6533 must be clean

Usually a few hours later the file system gets corrupted:

  NILFS: bad btree node (blocknr=8748107): level = 0, flags = 0x0, nchildren = 0
  NILFS error (device sdc1): nilfs_bmap_last_key: broken bmap (inode number=114660)

The issue can be reproduced with a file system that is nearly full and
with the cleaner running, while some IO intensive task is running.
Although it is quite hard to reproduce.

This is what happens:

 1. The cleaner starts the segment construction
 2. nilfs_segctor_collect is called
 3. sc_stage is on NILFS_ST_SUFILE and segments are freed
 4. sc_stage is on NILFS_ST_DAT current segment is full
 5. nilfs_segctor_extend_segments is called, which
    allocates a new segment
 6. The new segment is one of the segments freed in step 3
 7. nilfs_sufile_cancel_freev is called and produces an error message
 8. Loop around and the collection starts again
 9. sc_stage is on NILFS_ST_SUFILE and segments are freed
    including the newly allocated segment, which will contain active
    data and can be allocated at a later time
10. A few hours later another segment construction allocates the
    segment and causes file system corruption

This can be prevented by simply reordering the statements.  If
nilfs_sufile_cancel_freev is called before nilfs_segctor_extend_segments
the freed segments are marked as dirty and cannot be allocated any more.
Signed-off-by: NAndreas Rohner <andreas.rohner@gmx.net>
Reviewed-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: NAndreas Rohner <andreas.rohner@gmx.net>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In case CONFIG_DEBUG_OBJECTS_WORK is defined, it is needed to
call destroy_work_on_stack() which frees the debug object to pair
with INIT_WORK_ONSTACK().
Signed-off-by: NLiu, Chuansheng <chuansheng.liu@intel.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

(cherry picked from commit 6f96b306)

With CRC check is enabled, if trying to set an attributes value just
equal to the maximum size of XATTR_SIZE_MAX would cause the v3 remote
attr write verification procedure failure, which would yield the back
trace like below:

<snip>
XFS (sda7): Internal error xfs_attr3_rmt_write_verify at line 191 of file fs/xfs/xfs_attr_remote.c
<snip>
Call Trace:
[<ffffffff816f0042>] dump_stack+0x45/0x56
[<ffffffffa0d99c8b>] xfs_error_report+0x3b/0x40 [xfs]
[<ffffffffa0d96edd>] ? _xfs_buf_ioapply+0x6d/0x390 [xfs]
[<ffffffffa0d99ce5>] xfs_corruption_error+0x55/0x80 [xfs]
[<ffffffffa0dbef6b>] xfs_attr3_rmt_write_verify+0x14b/0x1a0 [xfs]
[<ffffffffa0d96edd>] ? _xfs_buf_ioapply+0x6d/0x390 [xfs]
[<ffffffffa0d97315>] ? xfs_bdstrat_cb+0x55/0xb0 [xfs]
[<ffffffffa0d96edd>] _xfs_buf_ioapply+0x6d/0x390 [xfs]
[<ffffffff81184cda>] ? vm_map_ram+0x31a/0x460
[<ffffffff81097230>] ? wake_up_state+0x20/0x20
[<ffffffffa0d97315>] ? xfs_bdstrat_cb+0x55/0xb0 [xfs]
[<ffffffffa0d9726b>] xfs_buf_iorequest+0x6b/0xc0 [xfs]
[<ffffffffa0d97315>] xfs_bdstrat_cb+0x55/0xb0 [xfs]
[<ffffffffa0d97906>] xfs_bwrite+0x46/0x80 [xfs]
[<ffffffffa0dbfa94>] xfs_attr_rmtval_set+0x334/0x490 [xfs]
[<ffffffffa0db84aa>] xfs_attr_leaf_addname+0x24a/0x410 [xfs]
[<ffffffffa0db8893>] xfs_attr_set_int+0x223/0x470 [xfs]
[<ffffffffa0db8b76>] xfs_attr_set+0x96/0xb0 [xfs]
[<ffffffffa0db13b2>] xfs_xattr_set+0x42/0x70 [xfs]
[<ffffffff811df9b2>] generic_setxattr+0x62/0x80
[<ffffffff811e0213>] __vfs_setxattr_noperm+0x63/0x1b0
[<ffffffff81307afe>] ? evm_inode_setxattr+0xe/0x10
[<ffffffff811e0415>] vfs_setxattr+0xb5/0xc0
[<ffffffff811e054e>] setxattr+0x12e/0x1c0
[<ffffffff811c6e82>] ? final_putname+0x22/0x50
[<ffffffff811c708b>] ? putname+0x2b/0x40
[<ffffffff811cc4bf>] ? user_path_at_empty+0x5f/0x90
[<ffffffff811bdfd9>] ? __sb_start_write+0x49/0xe0
[<ffffffff81168589>] ? vm_mmap_pgoff+0x99/0xc0
[<ffffffff811e07df>] SyS_setxattr+0x8f/0xe0
[<ffffffff81700c2d>] system_call_fastpath+0x1a/0x1f

Tests:
    setfattr -n user.longxattr -v `perl -e 'print "A"x65536'` testfile

This patch fix it to check the remote EA size is greater than the
XATTR_SIZE_MAX rather than more than or equal to it, because it's
valid if the specified EA value size is equal to the limitation as
per VFS setxattr interface.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

(cherry picked from commit 85dd0707)

Commit f5a44db5 introduced a regression on filesystems created with
the bigalloc feature (cluster size > blocksize).  It causes xfstests
generic/006 and /013 to fail with an unexpected JBD2 failure and
transaction abort that leaves the test file system in a read only state.
Other xfstests run on bigalloc file systems are likely to fail as well.

The cause is the accidental use of a cluster mask where a cluster
offset was needed in ext4_ext_map_blocks().
Signed-off-by: NEric Whitney <enwlinux@gmail.com>

The EPOLL_CTL_DEL path of epoll contains a classic, ab-ba deadlock.
That is, epoll_ctl(a, EPOLL_CTL_DEL, b, x), will deadlock with
epoll_ctl(b, EPOLL_CTL_DEL, a, x).  The deadlock was introduced with
commmit 67347fe4 ("epoll: do not take global 'epmutex' for simple
topologies").

The acquistion of the ep->mtx for the destination 'ep' was added such
that a concurrent EPOLL_CTL_ADD operation would see the correct state of
the ep (Specifically, the check for '!list_empty(&f.file->f_ep_links')

However, by simply not acquiring the lock, we do not serialize behind
the ep->mtx from the add path, and thus may perform a full path check
when if we had waited a little longer it may not have been necessary.
However, this is a transient state, and performing the full loop
checking in this case is not harmful.

The important point is that we wouldn't miss doing the full loop
checking when required, since EPOLL_CTL_ADD always locks any 'ep's that
its operating upon.  The reason we don't need to do lock ordering in the
add path, is that we are already are holding the global 'epmutex'
whenever we do the double lock.  Further, the original posting of this
patch, which was tested for the intended performance gains, did not
perform this additional locking.
Signed-off-by: NJason Baron <jbaron@akamai.com>
Cc: Nathan Zimmer <nzimmer@sgi.com>
Cc: Eric Wong <normalperson@yhbt.net>
Cc: Nelson Elhage <nelhage@nelhage.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

GLOCK_BUG_ON() might call this function without RCU read lock. Make sure that
RCU read lock is held when using task_struct returned from pid_task().
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Set FILE_CREATED on O_CREAT|O_EXCL.

cifs code didn't change during commit 116cc022

Kernel bugzilla 66251
Signed-off-by: NShirish Pargaonkar <spargaonkar@suse.com>
Acked-by: NJeff Layton <jlayton@redhat.com>
CC: Stable <stable@kernel.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

When we obtain tcon from cifs_sb, we use cifs_sb_tlink() to first obtain
tlink which also grabs a reference to it. We do not drop this reference
to tlink once we are done with the call.

The patch fixes this issue by instead passing tcon as a parameter and
avoids having to obtain a reference to the tlink. A lookup for the tcon
is already made in the calling functions and this way we avoid having to
re-run the lookup. This is also consistent with the argument list for
other similar calls for M-F symlinks.

We should also return an ENOSYS when we do not find a protocol specific
function to lookup the MF Symlink data.
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
CC: Stable <stable@kernel.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

Signed-off-by: NSteve French <smfrench@gmail.com>
Signed-off-by: NGregor Beck <gbeck@sernet.de>
Reviewed-by: NJeff Layton <jlayton@redhat.com>

Since commit 36bc08cc ("fs/aio: Add support to aio ring pages
migration") the aio ring setup code has used a special per-ring backing
inode for the page allocations, rather than just using random anonymous
pages.

However, rather than remembering the pages as it allocated them, it
would allocate the pages, insert them into the file mapping (dirty, so
that they couldn't be free'd), and then forget about them.  And then to
look them up again, it would mmap the mapping, and then use
"get_user_pages()" to get back an array of the pages we just created.

Now, not only is that incredibly inefficient, it also leaked all the
pages if the mmap failed (which could happen due to excessive number of
mappings, for example).

So clean it all up, making it much more straightforward.  Also remove
some left-overs of the previous (broken) mm_populate() usage that was
removed in commit d6c355c7 ("aio: fix race in ring buffer page
lookup introduced by page migration support") but left the pointless and
now misleading MAP_POPULATE flag around.
Tested-and-acked-by: NBenjamin LaHaise <bcrl@kvack.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The arbitrary restriction on page counts offered by the core
migrate_page_move_mapping() code results in rather suspicious looking
fiddling with page reference counts in the aio_migratepage() operation.
To fix this, make migrate_page_move_mapping() take an extra_count parameter
that allows aio to tell the code about its own reference count on the page
being migrated.

While cleaning up aio_migratepage(), make it validate that the old page
being passed in is actually what aio_migratepage() expects to prevent
misbehaviour in the case of races.
Signed-off-by: NBenjamin LaHaise <bcrl@kvack.org>

e34ecee2 reworked the percpu reference
counting to correct a bug trinity found.  Unfortunately, the change lead
to kioctxes being leaked because there was no final reference count to
put.  Add that reference count back in to fix things.
Signed-off-by: NBenjamin LaHaise <bcrl@kvack.org>
Cc: stable@vger.kernel.org

Some pstore backing devices use on board flash as persistent
storage. These have limited numbers of write cycles so it
is a poor idea to use them from high frequency operations.
Signed-off-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The missing casts can cause the high 64-bits of the physical blocks to
be lost.  Set up new macros which allows us to make sure the right
thing happen, even if at some point we end up supporting larger
logical block numbers.

Thanks to the Emese Revfy and the PaX security team for reporting this
issue.
Reported-by: NPaX Team <pageexec@freemail.hu>
Reported-by: Emese Revfy <re.emese@gmail.com>                                 
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

We need to wait for any outstanding DIO to complete in a couple
of situations. Firstly, in case we are changing out of deferred
mode (in inode_go_sync) where GLF_DIRTY will not be set. That
call could be prefixed with a test for gl_state == LM_ST_DEFERRED
but it doesn't seem worth it bearing in mind that the test for
outstanding DIO is very quick anyway, in the usual case that there
is none.

The second case is in inode_go_lock which will catch the cases
where we have a cached EX lock, but where we grant deferred locks
against it so that there is no glock state transistion. We only
need to wait if the state is not deferred, since DIO is valid
anyway in that state.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

In patch 209806ab we allowed
local deferred locks to be granted against a cached exclusive
lock. That opened up a corner case which this patch now
fixes.

The solution to the problem is to check whether we have cached
pages each time we do direct I/O and if so to unmap, flush
and invalidate those pages. Since the glock state machine
normally does that for us, mostly the code will be a no-op.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Akira-san has been reporting rare deadlocks of his machine when running
xfstests test 269 on ext4 filesystem. The problem turned out to be in
ext4_da_reserve_metadata() and ext4_da_reserve_space() which called
ext4_should_retry_alloc() while holding i_data_sem. Since
ext4_should_retry_alloc() can force a transaction commit, this is a
lock ordering violation and leads to deadlocks.

Fix the problem by just removing the retry loops. These functions should
just report ENOSPC to the caller (e.g. ext4_da_write_begin()) and that
function must take care of retrying after dropping all necessary locks.
Reported-and-tested-by: NAkira Fujita <a-fujita@rs.jp.nec.com>
Reviewed-by: NZheng Liu <wenqing.lz@taobao.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

If we are doing aysnc writeback of metadata, we can get write errors
but have nobody to report them to. At the moment, we simply attempt
to reissue the write from io completion in the hope that it's a
transient error.

When it's not a transient error, the buffer is stuck forever in
this loop, and we cannot break out of it. Eventually, unmount will
hang because the AIL cannot be emptied and everything goes downhill
from them.

To solve this problem, only retry the write IO once before aborting
it. We don't throw the buffer away because some transient errors can
last minutes (e.g.  FC path failover) or even hours (thin
provisioned devices that have run out of backing space) before they
go away. Hence we really want to keep trying until we can't try any
more.

Because the buffer was not cleaned, however, it does not get removed
from the AIL and hence the next pass across the AIL will start IO on
it again. As such, we still get the "retry forever" semantics that
we currently have, but we allow other access to the buffer in the
mean time. Meanwhile the filesystem can continue to modify the
buffer and relog it, so the IO errors won't hang the log or the
filesystem.

Now when we are pushing the AIL, we can see all these "permanent IO
error" buffers and we can issue a warning about failures before we
retry the IO. We can also catch these buffers when unmounting an
issue a corruption warning, too.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

When swalloc is specified as a mount option, allocations are
supposed to be aligned to the stripe width rather than the stripe
unit of the underlying filesystem. However, it does not do this.

What the implementation does is round up the allocation size to a
stripe width, hence ensuring that all allocations span a full stripe
width. It does not, however, ensure that that allocation is aligned
to a stripe width, and hence the allocations can span multiple
underlying stripes and so still see RMW cycles for things like
direct IO on MD RAID.

So, if the swalloc mount option is set, change the allocation
alignment in xfs_bmap_btalloc() to use the stripe width rather than
the stripe unit.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

The xfsbdstrat helper is a small but useless wrapper for xfs_buf_iorequest that
handles the case of a shut down filesystem.  Most of the users have private,
uncached buffers that can just be freed in this case, but the complex error
handling in xfs_bioerror_relse messes up the case when it's called without
a locked buffer.

Remove xfsbdstrat and opencode the error handling in the callers.  All but
one can simply return an error and don't need to deal with buffer state,
and the one caller that cares about the buffer state could do with a major
cleanup as well, but we'll defer that to later.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

The function xfs_bmap_isaeof() is used to indicate that an
allocation is occurring at or past the end of file, and as such
should be aligned to the underlying storage geometry if possible.

Commit 27a3f8f2 ("xfs: introduce xfs_bmap_last_extent") changed the
behaviour of this function for empty files - it turned off
allocation alignment for this case accidentally. Hence large initial
allocations from direct IO are not getting correctly aligned to the
underlying geometry, and that is cause write performance to drop in
alignment sensitive configurations.

Fix it by considering allocation into empty files as requiring
aligned allocation again.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

(cherry picked from commit f9b395a8)

xfs_quota(8) will hang up if trying to turn group/project quota off
before the user quota is off, this could be 100% reproduced by:
  # mount -ouquota,gquota /dev/sda7 /xfs
  # mkdir /xfs/test
  # xfs_quota -xc 'off -g' /xfs <-- hangs up
  # echo w > /proc/sysrq-trigger
  # dmesg

  SysRq : Show Blocked State
  task                        PC stack   pid father
  xfs_quota       D 0000000000000000     0 27574   2551 0x00000000
  [snip]
  Call Trace:
  [<ffffffff81aaa21d>] schedule+0xad/0xc0
  [<ffffffff81aa327e>] schedule_timeout+0x35e/0x3c0
  [<ffffffff8114b506>] ? mark_held_locks+0x176/0x1c0
  [<ffffffff810ad6c0>] ? call_timer_fn+0x2c0/0x2c0
  [<ffffffffa0c25380>] ? xfs_qm_shrink_count+0x30/0x30 [xfs]
  [<ffffffff81aa3306>] schedule_timeout_uninterruptible+0x26/0x30
  [<ffffffffa0c26155>] xfs_qm_dquot_walk+0x235/0x260 [xfs]
  [<ffffffffa0c059d8>] ? xfs_perag_get+0x1d8/0x2d0 [xfs]
  [<ffffffffa0c05805>] ? xfs_perag_get+0x5/0x2d0 [xfs]
  [<ffffffffa0b7707e>] ? xfs_inode_ag_iterator+0xae/0xf0 [xfs]
  [<ffffffffa0c22280>] ? xfs_trans_free_dqinfo+0x50/0x50 [xfs]
  [<ffffffffa0b7709f>] ? xfs_inode_ag_iterator+0xcf/0xf0 [xfs]
  [<ffffffffa0c261e6>] xfs_qm_dqpurge_all+0x66/0xb0 [xfs]
  [<ffffffffa0c2497a>] xfs_qm_scall_quotaoff+0x20a/0x5f0 [xfs]
  [<ffffffffa0c2b8f6>] xfs_fs_set_xstate+0x136/0x180 [xfs]
  [<ffffffff8136cf7a>] do_quotactl+0x53a/0x6b0
  [<ffffffff812fba4b>] ? iput+0x5b/0x90
  [<ffffffff8136d257>] SyS_quotactl+0x167/0x1d0
  [<ffffffff814cf2ee>] ? trace_hardirqs_on_thunk+0x3a/0x3f
  [<ffffffff81abcd19>] system_call_fastpath+0x16/0x1b

It's fine if we turn user quota off at first, then turn off other
kind of quotas if they are enabled since the group/project dquot
refcount is decreased to zero once the user quota if off. Otherwise,
those dquots refcount is non-zero due to the user dquot might refer
to them as hint(s).  Hence, above operation cause an infinite loop
at xfs_qm_dquot_walk() while trying to purge dquot cache.

This problem has been around since Linux 3.4, it was introduced by:
  [ b84a3a96 xfs: remove the per-filesystem list of dquots ]

Originally we will release the group dquot pointers because the user
dquots maybe carrying around as a hint via xfs_qm_detach_gdquots().
However, with above change, there is no such work to be done before
purging group/project dquot cache.

In order to solve this problem, this patch introduces a special routine
xfs_qm_dqpurge_hints(), and it would release the group/project dquot
pointers the user dquots maybe carrying around as a hint, and then it
will proceed to purge the user dquot cache if requested.

Cc: stable@vger.kernel.org
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

(cherry picked from commit df8052e7)

For CRC enabled v5 super block, change a file's ownership can simply
trigger an ASSERT failure at xfs_setattr_nonsize() if both group and
project quota are enabled, i.e,

[  305.337609] XFS: Assertion failed: !XFS_IS_PQUOTA_ON(mp), file: fs/xfs/xfs_iops.c, line: 621
[  305.339250] Kernel BUG at ffffffffa0a7fa32 [verbose debug info unavailable]
[  305.383939] Call Trace:
[  305.385536]  [<ffffffffa0a7d95a>] xfs_setattr_nonsize+0x69a/0x720 [xfs]
[  305.387142]  [<ffffffffa0a7dea9>] xfs_vn_setattr+0x29/0x70 [xfs]
[  305.388727]  [<ffffffff811ca388>] notify_change+0x1a8/0x350
[  305.390298]  [<ffffffff811ac39d>] chown_common+0xfd/0x110
[  305.391868]  [<ffffffff811ad6bf>] SyS_fchownat+0xaf/0x110
[  305.393440]  [<ffffffff811ad760>] SyS_lchown+0x20/0x30
[  305.394995]  [<ffffffff8170f7dd>] system_call_fastpath+0x1a/0x1f
[  305.399870] RIP  [<ffffffffa0a7fa32>] assfail+0x22/0x30 [xfs]

This fix adjust the assertion to check if the super block support both
quota inodes or not.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

(cherry picked from commit 5a01dd54)

After the previous fix, there still has another ASSERT failure if turning
off any type of quota while fsstress is running at the same time.

Backtrace in this case:

[   50.867897] XFS: Assertion failed: XFS_IS_GQUOTA_ON(mp), file: fs/xfs/xfs_qm.c, line: 2118
[   50.867924] ------------[ cut here ]------------
... <snip>
[   50.867957] Kernel BUG at ffffffffa0b55a32 [verbose debug info unavailable]
[   50.867999] invalid opcode: 0000 [#1] SMP
[   50.869407] Call Trace:
[   50.869446]  [<ffffffffa0bc408a>] xfs_qm_vop_create_dqattach+0x19a/0x2d0 [xfs]
[   50.869512]  [<ffffffffa0b9cc45>] xfs_create+0x5c5/0x6a0 [xfs]
[   50.869564]  [<ffffffffa0b5307c>] xfs_vn_mknod+0xac/0x1d0 [xfs]
[   50.869615]  [<ffffffffa0b531d6>] xfs_vn_mkdir+0x16/0x20 [xfs]
[   50.869655]  [<ffffffff811becd5>] vfs_mkdir+0x95/0x130
[   50.869689]  [<ffffffff811bf63a>] SyS_mkdirat+0xaa/0xe0
[   50.869723]  [<ffffffff811bf689>] SyS_mkdir+0x19/0x20
[   50.869757]  [<ffffffff8170f7dd>] system_call_fastpath+0x1a/0x1f
[   50.869793] Code: 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 <snip>
[   50.870003] RIP  [<ffffffffa0b55a32>] assfail+0x22/0x30 [xfs]
[   50.870050]  RSP <ffff88002941fd60>
[   50.879251] ---[ end trace c93a2b342341c65b ]---

We're hitting the ASSERT(XFS_IS_*QUOTA_ON(mp)) in xfs_qm_vop_create_dqattach(),
however the assertion itself is not right IMHO.  While performing quota off, we
firstly clear the XFS_*QUOTA_ACTIVE bit(s) from struct xfs_mount without taking
any special locks, see xfs_qm_scall_quotaoff().  Hence there is no guarantee
that the desired quota is still active.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

(cherry picked from commit 37eb9706)

Fix the leak of kernel memory in xfs_dir2_node_removename()
when xfs_dir2_leafn_remove() returns an error code.
Signed-off-by: NMark Tinguely <tinguely@sgi.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

(cherry picked from commit ef701600)

This patch fixes a slab memory leak that sometimes can occur
for files with a very short lifespan. The problem occurs when
a dinode is deleted before it has gotten to the journal properly.
In the leak scenario, the bd object is pinned for journal
committment (queued to the metadata buffers queue: sd_log_le_buf)
but is subsequently unpinned and dequeued before it finds its way
to the ail or the revoke queue. In this rare circumstance, the bd
object needs to be freed from slab memory, or it is forgotten.
We have to be very careful how we do it, though, because
multiple processes can call gfs2_remove_from_journal. In order to
avoid double-frees, only the process that does the unpinning is
allowed to free the bd.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>