Add two functions xfs_create_tmpfile() and xfs_vn_tmpfile()
to support O_TMPFILE file creation.

In contrast to xfs_create(), xfs_create_tmpfile() has a different
log reservation to the regular file creation because there is no
directory modification, and doesn't check if an entry can be added
to the directory, but the reservation quotas is required appropriately,
and finally its inode is added to the unlinked list.

xfs_vn_tmpfile() add one O_TMPFILE method to VFS interface and directly
invoke xfs_create_tmpfile().
Signed-off-by: NZhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

It will be reused by the O_TMPFILE creation function.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NZhi Yong Wu <wuzhy@linux.vnet.ibm.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>

rec.ir_startino is an agino rather than an ino.  Use the correct macro
when dealing with it in xfs_difree.
Signed-off-by: NBen Myers <bpm@sgi.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

If we are using a large directory block size, and memory becomes
fragmented, we can get memory allocation failures trying to
kmem_alloc(64k) for a temporary buffer. However, there is not need
for a directory buffer sized allocation, as the end result ends up
in the inode literal area. This is, at most, slightly less than 2k
of space, and hence we don't need an allocation larger than that
fora temporary buffer.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

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>

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>

Split out a xfs_setattr_time helper to share code between truncate and
regular setattr similar to xfs_setattr_mode.  I might also have another
caller growing for this in the near future.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Remove the pointless tp argument, and properly align the local variable
declarations.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

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>

The xfs_quota_priv header file is only included by xfs_qm header and
there is no much users for its contents, hence we can move those stuff
to xfs_qm header file and kill it.

This patch also remove an unused macro DQFLAGTO_TYPESTR.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

In xfs_qm_scall_trunc_qfiles(), we ignore the error if failed to remove
the users quota metadata and proceed to remove groups and projects if
they are being there.  However, in user space, the remove operation will
break and return if failed to remove any kind of quota.
Also for v5 super block, we can enabled both group and project quota at
the same time, in this case the current error handling will cover the
group error with projects but they might failed due to different reasons.

It seems we'd better the error handling consistent to the user space and
don't trying to remove another kind of quota metadata if the previous
operation is failed.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

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>

Recovery builds a list of items on the transaction's
r_itemq head. Normally these items are committed and freed.
But in the event of a recovery error, these allocations
are leaked.

If the error occurs during item reordering, then reconstruct
the r_itemq list before deleting the list to avoid leaking
the entries that were on one of the temporary lists.
Signed-off-by: NMark Tinguely <tinguely@sgi.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Currently notify_change directly updates i_version for size updates,
which not only is counter to how all other fields are updated through
struct iattr, but also breaks XFS, which need inode updates to happen
under its own lock, and synchronized to the structure that gets written
to the log.

Remove the update in the common code, and it to btrfs and ext4,
XFS already does a proper updaste internally and currently gets a
double update with the existing code.

IMHO this is 3.13 and -stable material and should go in through the XFS
tree.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAndreas Dilger <adilger@dilger.ca>
Acked-by: NJan Kara <jack@suse.cz>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NChris Mason <clm@fb.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

This loop in xfs_growfs_data_private() is incorrect for V4
superblocks filesystems:

		for (bucket = 0; bucket < XFS_AGFL_SIZE(mp); bucket++)
			agfl->agfl_bno[bucket] = cpu_to_be32(NULLAGBLOCK);

For V4 filesystems, we don't have a agfl header structure, and so
XFS_AGFL_SIZE() returns an entire sector's worth of entries, which
we then index from an offset into the sector. Hence: buffer overrun.

This problem was introduced in 3.10 by commit 77c95bba ("xfs: add
CRC checks to the AGFL") which changed the AGFL structure but failed
to update the growfs code to handle the different structures.

Fix it by using the correct offset into the buffer for both V4 and
V5 filesystems.

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

For discard operation, we should return EINVAL if the given range length
is less than a block size, otherwise it will go through the file system
to discard data blocks as the end range might be evaluated to -1, e.g,
# fstrim -v -o 0 -l 100 /xfs7
/xfs7: 9811378176 bytes were trimmed

This issue can be triggered via xfstests/generic/288.

Also, it seems to get the request queue pointer via bdev_get_queue()
instead of the hard code pointer dereference is not a bad thing.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NCarlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

If we allocate less than sizeof(struct attrlist) then we end up
corrupting memory or doing a ZERO_PTR_SIZE dereference.

This can only be triggered with CAP_SYS_ADMIN.
Reported-by: NNico Golde <nico@ngolde.de>
Reported-by: NFabian Yamaguchi <fabs@goesec.de>
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@redhat.com.>
Signed-off-by: NBen Myers <bpm@sgi.com>

The "verbose" argument to xfs_setsize_buftarg_flags() has been
unused since:

ffe37436 xfs: stop using the page cache to back the buffer cache

Remove it, and fold the function into xfs_setsize_buftarg()
now that there's no need for different types of callers.

Fix inconsistent comment spacing while we're at it.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Failure to grab reference to parent dentry should go through the
same cleanup as nd->seq mismatch.  As it is, we might end up with
caller thinking it needs to path_put() nd->root, with obvious
nasty results once we'd hit that bug enough times to drive the
refcount of root dentry all the way to zero...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This tool hasn't been maintained in over a decade, and is pretty much
useless these days.  Let's pretend it never happened.

Also remove a long-dead email address.
Signed-off-by: NDave Jones <davej@fedoraproject.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit 54d71145.

The root cause of these "inverted" sysfs removals have now been found,
so there is no need for this patch.  Keep this functionality around so
that this type of error doesn't show up in driver code again.

Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Change cifs.ko to using CIFS_IOCTL_COPYCHUNK instead
of BTRFS_IOC_CLONE to avoid confusion about whether
copy-on-write is required or optional for this operation.

SMB2/SMB3 copyoffload had used the BTRFS_IOC_CLONE ioctl since
they both speed up copy by offloading the copy rather than
passing many read and write requests back and forth and both have
identical syntax (passing file handles), but for SMB2/SMB3
CopyChunk the server is not required to use copy-on-write
to make a copy of the file (although some do), and Christoph
has commented that since CopyChunk does not require
copy-on-write we should not reuse BTRFS_IOC_CLONE.

This patch renames the ioctl to use a cifs specific IOCTL
CIFS_IOCTL_COPYCHUNK.  This ioctl is particularly important
for SMB2/SMB3 since large file copy over the network otherwise
can be very slow, and with this is often more than 100 times
faster putting less load on server and client.

Note that if a copy syscall is ever introduced, depending on
its requirements/format it could end up using one of the other
three methods that CIFS/SMB2/SMB3 can do for copy offload,
but this method is particularly useful for file copy
and broadly supported (not just by Samba server).
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NDavid Disseldorp <ddiss@samba.org>

ceph_osdc_readpages() returns number of bytes read, currently,
the code only allocate full-zero page into fscache, this patch
fixes this.
Signed-off-by: NLi Wang <liwang@ubuntukylin.com>
Reviewed-by: NMilosz Tanski <milosz@adfin.com>
Reviewed-by: NSage Weil <sage@inktank.com>

We also need to wake up 'safe' waiters if error occurs or request
aborted. Otherwise sync(2)/fsync(2) may hang forever.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: NSage Weil <sage@inktank.com>

Aborted requests usually get cleared when the reply is received.
If MDS crashes, no reply will be received. So we need to cleanup
aborted requests when re-sending requests.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NGreg Farnum <greg@inktank.com>
Signed-off-by: NSage Weil <sage@inktank.com>

When a cap get released while composing the cap reconnect message.
We should skip queuing the release message if the cap hasn't been
added to the cap reconnect message.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

It's possible that some caps get released while composing the cap
reconnect message.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

call __queue_cap_release() in __ceph_remove_cap(), this avoids
acquiring s_cap_lock twice.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

The following two commits implemented mmap support in the regular file
path and merged bin file support into the regular path.

 73d97146 ("sysfs: copy bin mmap support from fs/sysfs/bin.c to fs/sysfs/file.c")
 3124eb16 ("sysfs: merge regular and bin file handling")

After the merge, the following commands trigger a spurious lockdep
warning.  "test-mmap-read" simply mmaps the file and dumps the
content.

  $ cat /sys/block/sda/trace/act_mask
  $ test-mmap-read /sys/devices/pci0000\:00/0000\:00\:03.0/resource0 4096

  ======================================================
  [ INFO: possible circular locking dependency detected ]
  3.12.0-work+ #378 Not tainted
  -------------------------------------------------------
  test-mmap-read/567 is trying to acquire lock:
   (&of->mutex){+.+.+.}, at: [<ffffffff8120a8df>] sysfs_bin_mmap+0x4f/0x120

  but task is already holding lock:
   (&mm->mmap_sem){++++++}, at: [<ffffffff8114b399>] vm_mmap_pgoff+0x49/0xa0

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #3 (&mm->mmap_sem){++++++}:
  ...
  -> #2 (sr_mutex){+.+.+.}:
  ...
  -> #1 (&bdev->bd_mutex){+.+.+.}:
  ...
  -> #0 (&of->mutex){+.+.+.}:
  ...

  other info that might help us debug this:

  Chain exists of:
   &of->mutex --> sr_mutex --> &mm->mmap_sem

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(&mm->mmap_sem);
				 lock(sr_mutex);
				 lock(&mm->mmap_sem);
    lock(&of->mutex);

   *** DEADLOCK ***

  1 lock held by test-mmap-read/567:
   #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff8114b399>] vm_mmap_pgoff+0x49/0xa0

  stack backtrace:
  CPU: 3 PID: 567 Comm: test-mmap-read Not tainted 3.12.0-work+ #378
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
   ffffffff81ed41a0 ffff880009441bc8 ffffffff81611ad2 ffffffff81eccb80
   ffff880009441c08 ffffffff8160f215 ffff880009441c60 ffff880009c75208
   0000000000000000 ffff880009c751e0 ffff880009c75208 ffff880009c74ac0
  Call Trace:
   [<ffffffff81611ad2>] dump_stack+0x4e/0x7a
   [<ffffffff8160f215>] print_circular_bug+0x2b0/0x2bf
   [<ffffffff8109ca0a>] __lock_acquire+0x1a3a/0x1e60
   [<ffffffff8109d6ba>] lock_acquire+0x9a/0x1d0
   [<ffffffff81615547>] mutex_lock_nested+0x67/0x3f0
   [<ffffffff8120a8df>] sysfs_bin_mmap+0x4f/0x120
   [<ffffffff8115d363>] mmap_region+0x3b3/0x5b0
   [<ffffffff8115d8ae>] do_mmap_pgoff+0x34e/0x3d0
   [<ffffffff8114b3ba>] vm_mmap_pgoff+0x6a/0xa0
   [<ffffffff8115be3e>] SyS_mmap_pgoff+0xbe/0x250
   [<ffffffff81008282>] SyS_mmap+0x22/0x30
   [<ffffffff8161a4d2>] system_call_fastpath+0x16/0x1b

This happens because one file nests sr_mutex, which nests mm->mmap_sem
under it, under of->mutex while mmap implementation naturally nests
of->mutex under mm->mmap_sem.  The warning is false positive as
of->mutex is per open-file and the two paths belong to two different
files.  This warning didn't trigger before regular and bin file
supports were merged because only bin file supported mmap and the
other side of locking happened only on regular files which used
equivalent but separate locking.

It'd be best if we give separate locking classes per file but we can't
easily do that.  Let's differentiate on ->mmap() for now.  Later we'll
add explicit file operations struct and can add per-ops lockdep key
there.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NDave Jones <davej@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit bcdde7e2 (sysfs: make __sysfs_remove_dir() recursive) changed
the behavior so that directory removals will be done recursively. This
means that the sysfs group might already be removed if its parent directory
has been removed.

The current code outputs warnings similar to following log snippet when it
detects that there is no group for the given kobject:

 WARNING: CPU: 0 PID: 4 at fs/sysfs/group.c:214 sysfs_remove_group+0xc6/0xd0()
 sysfs group ffffffff81c6f1e0 not found for kobject 'host7'
 Modules linked in:
 CPU: 0 PID: 4 Comm: kworker/0:0 Not tainted 3.12.0+ #13
 Hardware name:                  /D33217CK, BIOS GKPPT10H.86A.0042.2013.0422.1439 04/22/2013
 Workqueue: kacpi_hotplug acpi_hotplug_work_fn
  0000000000000009 ffff8801002459b0 ffffffff817daab1 ffff8801002459f8
  ffff8801002459e8 ffffffff810436b8 0000000000000000 ffffffff81c6f1e0
  ffff88006d440358 ffff88006d440188 ffff88006e8b4c28 ffff880100245a48
 Call Trace:
  [<ffffffff817daab1>] dump_stack+0x45/0x56
  [<ffffffff810436b8>] warn_slowpath_common+0x78/0xa0
  [<ffffffff81043727>] warn_slowpath_fmt+0x47/0x50
  [<ffffffff811ad319>] ? sysfs_get_dirent_ns+0x49/0x70
  [<ffffffff811ae526>] sysfs_remove_group+0xc6/0xd0
  [<ffffffff81432f7e>] dpm_sysfs_remove+0x3e/0x50
  [<ffffffff8142a0d0>] device_del+0x40/0x1b0
  [<ffffffff8142a24d>] device_unregister+0xd/0x20
  [<ffffffff8144131a>] scsi_remove_host+0xba/0x110
  [<ffffffff8145f526>] ata_host_detach+0xc6/0x100
  [<ffffffff8145f578>] ata_pci_remove_one+0x18/0x20
  [<ffffffff812e8f48>] pci_device_remove+0x28/0x60
  [<ffffffff8142d854>] __device_release_driver+0x64/0xd0
  [<ffffffff8142d8de>] device_release_driver+0x1e/0x30
  [<ffffffff8142d257>] bus_remove_device+0xf7/0x140
  [<ffffffff8142a1b1>] device_del+0x121/0x1b0
  [<ffffffff812e43d4>] pci_stop_bus_device+0x94/0xa0
  [<ffffffff812e437b>] pci_stop_bus_device+0x3b/0xa0
  [<ffffffff812e437b>] pci_stop_bus_device+0x3b/0xa0
  [<ffffffff812e44dd>] pci_stop_and_remove_bus_device+0xd/0x20
  [<ffffffff812fc743>] trim_stale_devices+0x73/0xe0
  [<ffffffff812fc78b>] trim_stale_devices+0xbb/0xe0
  [<ffffffff812fc78b>] trim_stale_devices+0xbb/0xe0
  [<ffffffff812fcb6e>] acpiphp_check_bridge+0x7e/0xd0
  [<ffffffff812fd90d>] hotplug_event+0xcd/0x160
  [<ffffffff812fd9c5>] hotplug_event_work+0x25/0x60
  [<ffffffff81316749>] acpi_hotplug_work_fn+0x17/0x22
  [<ffffffff8105cf3a>] process_one_work+0x17a/0x430
  [<ffffffff8105db29>] worker_thread+0x119/0x390
  [<ffffffff8105da10>] ? manage_workers.isra.25+0x2a0/0x2a0
  [<ffffffff81063a5d>] kthread+0xcd/0xf0
  [<ffffffff81063990>] ? kthread_create_on_node+0x180/0x180
  [<ffffffff817eb33c>] ret_from_fork+0x7c/0xb0
  [<ffffffff81063990>] ? kthread_create_on_node+0x180/0x180

On this particular machine I see ~16 of these message during Thunderbolt
hot-unplug.

Fix this in similar way that was done for sysfs_remove_one() by checking
if the parent directory has already been removed and bailing out early.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

A race window in configfs, it starts from one dentry is UNHASHED and end
before configfs_d_iput is called.  In this window, if a lookup happen,
since the original dentry was UNHASHED, so a new dentry will be
allocated, and then in configfs_attach_attr(), sd->s_dentry will be
updated to the new dentry.  Then in configfs_d_iput(),
BUG_ON(sd->s_dentry != dentry) will be triggered and system panic.

sys_open:                     sys_close:
 ...                           fput
                                dput
                                 dentry_kill
                                  __d_drop <--- dentry unhashed here,
                                           but sd->dentry still point
                                           to this dentry.

 lookup_real
  configfs_lookup
   configfs_attach_attr---> update sd->s_dentry
                            to new allocated dentry here.

                                   d_kill
                                     configfs_d_iput <--- BUG_ON(sd->s_dentry != dentry)
                                                     triggered here.

To fix it, change configfs_d_iput to not update sd->s_dentry if
sd->s_count > 2, that means there are another dentry is using the sd
beside the one that is going to be put.  Use configfs_dirent_lock in
configfs_attach_attr to sync with configfs_d_iput.

With the following steps, you can reproduce the bug.

1. enable ocfs2, this will mount configfs at /sys/kernel/config and
   fill configure in it.

2. run the following script.
	while [ 1 ]; do cat /sys/kernel/config/cluster/$your_cluster_name/idle_timeout_ms > /dev/null; done &
	while [ 1 ]; do cat /sys/kernel/config/cluster/$your_cluster_name/idle_timeout_ms > /dev/null; done &
Signed-off-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In the case that atomic_open calls finish_no_open() with
the dentry that was supplied to gfs2_atomic_open() an
extra reference count is required. This patch fixes that
issue preventing a bug trap triggering at umount time.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Commit [e66cf161: GFS2: Use lockref for glocks] replaced call:
    atomic_read(&gi->gl->gl_ref) == 0
with:
    __lockref_is_dead(&gl->gl_lockref)
therefore changing how gl is accessed, from gi->gl to plan gl.
However, gl can be a NULL pointer, and so gi->gl needs to be
used instead (which is guaranteed not to be NULL because fo
the while loop checking that condition).
Signed-off-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Reflect the current status. Portions of the text taken from the
wiki pages.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

The data type of max_sectors in queue settings is unsigned int.  But
this value is stored to the local variable whose type is unsigned short
in bio_size_ok().  This can cause unexpected result when max_sectors >
0xffff.

Cc: Chris Mason <chris.mason@fusionio.com>
Cc: linux-btrfs@vger.kernel.org
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Doing an if statement to test some condition to know if we should
trigger a tracepoint is pointless when tracing is disabled. This just
adds overhead and wastes a branch prediction. This is why the
TRACE_EVENT_CONDITION() was created. It places the check inside the jump
label so that the branch does not happen unless tracing is enabled.

That is, instead of doing:

	if (em)
		trace_btrfs_get_extent(root, em);

Which is basically this:

	if (em)
		if (static_key(trace_btrfs_get_extent)) {

Using a TRACE_EVENT_CONDITION() we can just do:

	trace_btrfs_get_extent(root, em);

And the condition trace event will do:

	if (static_key(trace_btrfs_get_extent)) {
		if (em) {
			...

The static key is a non conditional jump (or nop) that is faster than
having to check if em is NULL or not.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>