*_read_cnt in ramoops_context need to be cleared during pstore ->open to
support mutli times getting the records.  The patch added missed
ftrace_read_cnt clearing and removed duplicate clearing in ramoops_probe.
Signed-off-by: NLiu ShuoX <shuox.liu@intel.com>
Cc: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Cc: Colin Cross <ccross@android.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Adds support for HFSX 'HasFolderCount' flag and a corresponding
'folderCount' field in folder records.  (For reference see
HFS_FOLDERCOUNT and kHFSHasFolderCountBit/kHFSHasFolderCountMask in
Apple's source code.)

Ignoring subfolder count leads to fs errors found by Mac:

  ...
  Checking catalog hierarchy.
  HasFolderCount flag needs to be set (id = 105)
  (It should be 0x10 instead of 0)
  Incorrect folder count in a directory (id = 2)
  (It should be 7 instead of 6)
  ...

Steps to reproduce:
 Format with "newfs_hfs -s /dev/diskXXX".
 Mount in Linux.
 Create a new directory in root.
 Unmount.
 Run "fsck_hfs /dev/diskXXX".

The patch handles directory creation, deletion, and rename.
Signed-off-by: NSergei Antonov <saproj@gmail.com>
Reviewed-by: NVyacheslav Dubeyko <slava@dubeyko.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The expected logic of proc_map_files_get_link() is either to return 0
and initialize 'path' or return an error and leave 'path' uninitialized.

By the time dname_to_vma_addr() returns 0 the corresponding vma may have
already be gone.  In this case the path is not initialized but the
return value is still 0.  This results in 'general protection fault'
inside d_path().

Steps to reproduce:

  CONFIG_CHECKPOINT_RESTORE=y

    fd = open(...);
    while (1) {
        mmap(fd, ...);
        munmap(fd, ...);
    }

  ls -la /proc/$PID/map_files

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=68991Signed-off-by: NArtem Fetishev <artem_fetishev@epam.com>
Signed-off-by: NAleksandr Terekhov <aleksandr_terekhov@epam.com>
Reported-by: <wiebittewas@gmail.com>
Acked-by: NPavel Emelyanov <xemul@parallels.com>
Acked-by: NCyrill Gorcunov <gorcunov@openvz.org>
Reviewed-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

instead of returning the flags by reference, we can just have the
low-level primitive return those in lower bits of unsigned long,
with struct file * derived from the rest.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Our write() system call has always been atomic in the sense that you get
the expected thread-safe contiguous write, but we haven't actually
guaranteed that concurrent writes are serialized wrt f_pos accesses, so
threads (or processes) that share a file descriptor and use "write()"
concurrently would quite likely overwrite each others data.

This violates POSIX.1-2008/SUSv4 Section XSI 2.9.7 that says:

 "2.9.7 Thread Interactions with Regular File Operations

  All of the following functions shall be atomic with respect to each
  other in the effects specified in POSIX.1-2008 when they operate on
  regular files or symbolic links: [...]"

and one of the effects is the file position update.

This unprotected file position behavior is not new behavior, and nobody
has ever cared.  Until now.  Yongzhi Pan reported unexpected behavior to
Michael Kerrisk that was due to this.

This resolves the issue with a f_pos-specific lock that is taken by
read/write/lseek on file descriptors that may be shared across threads
or processes.
Reported-by: NYongzhi Pan <panyongzhi@gmail.com>
Reported-by: NMichael Kerrisk <mtk.manpages@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

If the open stateid could not be recovered, or the file locks were lost,
then we should fail the truncate() operation altogether.
Reported-by: NAndy Adamson <andros@netapp.com>
Link: http://lkml.kernel.org/r/1393954269-3974-1-git-send-email-andros@netapp.comSigned-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: NAndy Adamson <andros@netapp.com>
Link: http://lkml.kernel.org/r/1393954269-3974-1-git-send-email-andros@netapp.comSigned-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

In commit 5521abfd (NFSv4: Resend the READ/WRITE RPC call
if a stateid change causes an error), we overloaded the return value of
nfs4_select_rw_stateid() to cause it to return -EWOULDBLOCK if an RPC
call is outstanding that would cause the NFSv4 lock or open stateid
to change.
That is all redundant when we actually copy the stateid used in the
read/write RPC call that failed, and check that against the current
stateid. It is doubly so, when we consider that in the NFSv4.1 case,
we also set the stateid's seqid to the special value '0', which means
'match the current valid stateid'.
Reported-by: NAndy Adamson <andros@netapp.com>
Link: http://lkml.kernel.org/r/1393954269-3974-1-git-send-email-andros@netapp.comSigned-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

When nfs4_set_rw_stateid() can fails by returning EIO to indicate that
the stateid is completely invalid, then it makes no sense to have it
trigger a retry of the READ or WRITE operation. Instead, we should just
have it fall through and attempt a recovery.

This fixes an infinite loop in which the client keeps replaying the same
bad stateid back to the server.
Reported-by: NAndy Adamson <andros@netapp.com>
Link: http://lkml.kernel.org/r/1393954269-3974-1-git-send-email-andros@netapp.com
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Current implementation of HFS+ driver has small issue with remount
option.  Namely, for example, you are unable to remount from RO mode
into RW mode by means of command "mount -o remount,rw /dev/loop0
/mnt/hfsplus".  Trying to execute sequence of commands results in an
error message:

  mount /dev/loop0 /mnt/hfsplus
  mount -o remount,ro /dev/loop0 /mnt/hfsplus
  mount -o remount,rw /dev/loop0 /mnt/hfsplus

  mount: you must specify the filesystem type

  mount -t hfsplus -o remount,rw /dev/loop0 /mnt/hfsplus

  mount: /mnt/hfsplus not mounted or bad option

The reason of such issue is failure of mount syscall:

  mount("/dev/loop0", "/mnt/hfsplus", 0x2282a60, MS_MGC_VAL|MS_REMOUNT, NULL) = -1 EINVAL (Invalid argument)

Namely, hfsplus_parse_options_remount() method receives empty "input"
argument and return false in such case.  As a result, hfsplus_remount()
returns -EINVAL error code.

This patch fixes the issue by means of return true for the case of empty
"input" argument in hfsplus_parse_options_remount() method.
Signed-off-by: NVyacheslav Dubeyko <slava@dubeyko.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Global quota files are accessed from different nodes.  Thus we cannot
cache offset of quota structure in the quota file after we drop our node
reference count to it because after that moment quota structure may be
freed and reallocated elsewhere by a different node resulting in
corruption of quota file.

Fix the problem by clearing dq_off when we are releasing dquot structure.
We also remove the DB_READ_B handling because it is useless -
DQ_ACTIVE_B is set iff DQ_READ_B is set.
Signed-off-by: NJan Kara <jack@suse.cz>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Reviewed-by: NMark Fasheh <mfasheh@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit bf6bddf1 ("mm: introduce compaction and migration for
ballooned pages") introduces page_count(page) into memory compaction
which dereferences page->first_page if PageTail(page).

This results in a very rare NULL pointer dereference on the
aforementioned page_count(page).  Indeed, anything that does
compound_head(), including page_count() is susceptible to racing with
prep_compound_page() and seeing a NULL or dangling page->first_page
pointer.

This patch uses Andrea's implementation of compound_trans_head() that
deals with such a race and makes it the default compound_head()
implementation.  This includes a read memory barrier that ensures that
if PageTail(head) is true that we return a head page that is neither
NULL nor dangling.  The patch then adds a store memory barrier to
prep_compound_page() to ensure page->first_page is set.

This is the safest way to ensure we see the head page that we are
expecting, PageTail(page) is already in the unlikely() path and the
memory barriers are unfortunately required.

Hugetlbfs is the exception, we don't enforce a store memory barrier
during init since no race is possible.
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Cc: Holger Kiehl <Holger.Kiehl@dwd.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The clean-up in commit 36281caa ended up removing a NULL pointer check
that is needed in order to prevent an Oops in
nfs_async_inode_return_delegation().
Reported-by: N"Yan, Zheng" <zheng.z.yan@intel.com>
Link: http://lkml.kernel.org/r/5313E9F6.2020405@intel.com
Fixes: 36281caa (NFSv4: Further clean-ups of delegation stateid validation)
Cc: stable@vger.kernel.org # 3.4+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

nfs4_release_lockowner needs to set the rpc_message reply to point to
the nfs4_sequence_res in order to avoid another Oopsable situation
in nfs41_assign_slot.

Fixes: fbd4bfd1 (NFS: Add nfs4_sequence calls for RELEASE_LOCKOWNER)
Cc: stable@vger.kernel.org # 3.12+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The rfc1002 length actually includes a type byte, which we aren't
masking off. In most cases, it's not a problem since the
RFC1002_SESSION_MESSAGE type is 0, but when doing a RFC1002 session
establishment, the type is non-zero and that throws off the returned
length.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Tested-by: NSachin Prabhu <sprabhu@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

As mount() and kill_sb() is not a one-to-one match, we shoudn't get
ns refcnt unconditionally in sysfs_mount(), and instead we should
get the refcnt only when kernfs_mount() allocated a new superblock.

v2:
- Changed the name of the new argument, suggested by Tejun.
- Made the argument optional, suggested by Tejun.

v3:
- Make the new argument as second-to-last arg, suggested by Tejun.
Signed-off-by: NLi Zefan <lizefan@huawei.com>
Acked-by: NTejun Heo <tj@kernel.org>
 ---
 fs/kernfs/mount.c      | 8 +++++++-
 fs/sysfs/mount.c       | 5 +++--
 include/linux/kernfs.h | 9 +++++----
 3 files changed, 15 insertions(+), 7 deletions(-)
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 7053aee2 "fsnotify: do not share events between notification
groups" used overflow event statically allocated in a group with the
size of the generic notification event. This causes problems because
some code looks at type specific parts of event structure and gets
confused by a random data it sees there and causes crashes.

Fix the problem by allocating overflow event with type corresponding to
the group type so code cannot get confused.
Signed-off-by: NJan Kara <jack@suse.cz>

If the event queue overflows when we are handling permission event, we
will never get response from userspace. So we must avoid waiting for it.
Change fsnotify_add_notify_event() to return whether overflow has
happened so that we can detect it in fanotify_handle_event() and act
accordingly.
Signed-off-by: NJan Kara <jack@suse.cz>

Currently we didn't initialize event's list head when we removed it from
the event list. Thus a detection whether overflow event is already
queued wasn't working. Fix it by always initializing the list head when
deleting event from a list.
Signed-off-by: NJan Kara <jack@suse.cz>

We had a bug discovered recently where an upper layer function
(cifs_iovec_write) could pass down a smb_rqst with an invalid amount of
data in it. The length of the SMB frame would be correct, but the rqst
struct would cause smb_send_rqst to send nearly 4GB of data.

This should never be the case. Add some sanity checking to the beginning
of smb_send_rqst that ensures that the amount of data we're going to
send agrees with the length in the RFC1002 header. If it doesn't, WARN()
and return -EIO to the upper layers.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Acked-by: NSachin Prabhu <sprabhu@redhat.com>
Reviewed-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NSteve French <smfrench@gmail.com>

and use generic_file_aio_write rather than __generic_file_aio_write
in cifs_writev.
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NSteve French <smfrench@gmail.com>

This reverts commit c4a391b5. Dave
Chinner <david@fromorbit.com> has reported the commit may cause some
inodes to be left out from sync(2). This is because we can call
redirty_tail() for some inode (which sets i_dirtied_when to current time)
after sync(2) has started or similarly requeue_inode() can set
i_dirtied_when to current time if writeback had to skip some pages. The
real problem is in the functions clobbering i_dirtied_when but fixing
that isn't trivial so revert is a safer choice for now.

CC: stable@vger.kernel.org # >= 3.13
Signed-off-by: NJan Kara <jack@suse.cz>

Given that bip->bip_iter.bi_size is decremented after bio_advance() ->
bio_integrity_advance() is called, the BUG_ON() in bio_integrity_verify()
ends up tripping in v3.14-rc1 code with the advent of immutable biovecs
in:

commit d57a5f7c
Author: Kent Overstreet <kmo@daterainc.com>
Date:   Sat Nov 23 17:20:16 2013 -0800

    bio-integrity: Convert to bvec_iter

Given that there is no easy way to ascertain the original bi_size
value, go ahead and drop this BUG_ON().
Reported-by: NSagi Grimberg <sagig@dev.mellanox.co.il>
Reported-by: NAkinobu Mita <akinobu.mita@gmail.com>
Acked-by: NMartin K. Petersen <martin.petersen@oracle.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: NJens Axboe <axboe@fb.com>

Currently last dqput() can race with dquot_scan_active() causing it to
call callback for an already deactivated dquot. The race is as follows:

CPU1					CPU2
  dqput()
    spin_lock(&dq_list_lock);
    if (atomic_read(&dquot->dq_count) > 1) {
     - not taken
    if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
      spin_unlock(&dq_list_lock);
      ->release_dquot(dquot);
        if (atomic_read(&dquot->dq_count) > 1)
         - not taken
					  dquot_scan_active()
					    spin_lock(&dq_list_lock);
					    if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
					     - not taken
					    atomic_inc(&dquot->dq_count);
					    spin_unlock(&dq_list_lock);
        - proceeds to release dquot
					    ret = fn(dquot, priv);
					     - called for inactive dquot

Fix the problem by making sure possible ->release_dquot() is finished by
the time we call the callback and new calls to it will notice reference
dquot_scan_active() has taken and bail out.

CC: stable@vger.kernel.org # >= 2.6.29
Signed-off-by: NJan Kara <jack@suse.cz>

UDF has two types of files - files with data stored in inode (ICB in
UDF terminology) and files with data stored in external data blocks. We
convert file from in-inode format to external format in
udf_file_aio_write() when we find out data won't fit into inode any
longer. However the following race between two O_APPEND writes can happen:

CPU1					CPU2
udf_file_aio_write()			udf_file_aio_write()
  down_write(&iinfo->i_data_sem);
  checks that i_size + count1 fits within inode
    => no need to convert
  up_write(&iinfo->i_data_sem);
					  down_write(&iinfo->i_data_sem);
					  checks that i_size + count2 fits
					    within inode => no need to convert
					  up_write(&iinfo->i_data_sem);
  generic_file_aio_write()
    - extends file by count1 bytes
					  generic_file_aio_write()
					    - extends file by count2 bytes

Clearly if count1 + count2 doesn't fit into the inode, we overwrite
kernel buffers beyond inode, possibly corrupting the filesystem as well.

Fix the problem by acquiring i_mutex before checking whether write fits
into the inode and using __generic_file_aio_write() afterwards which
puts check and write into one critical section.
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NJan Kara <jack@suse.cz>

Do not return an error when nfs4_copy_delegation_stateid succeeds.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Link: http://lkml.kernel.org/r/1392737765-41942-1-git-send-email-andros@netapp.com
Fixes: ef1820f9 (NFSv4: Don't try to recover NFSv4 locks when...)
Cc: NeilBrown <neilb@suse.de>
Cc: stable@vger.kernel.org # 3.12+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Today, if

xfs_sb_read_verify
  xfs_sb_verify
    xfs_mount_validate_sb

detects superblock corruption, it'll be extremely noisy, dumping
2 stacks, 2 hexdumps, etc.

This is because we call XFS_CORRUPTION_ERROR in xfs_mount_validate_sb
as well as in xfs_sb_read_verify.

Also, *any* errors in xfs_mount_validate_sb which are not corruption
per se; things like too-big-blocksize, bad version, bad magic, v1 dirs,
rw-incompat etc - things which do not return EFSCORRUPTED - will
still do the whole XFS_CORRUPTION_ERROR spew when xfs_sb_read_verify
sees any error at all.  And it suggests to the user that they
should run xfs_repair, even if the root cause of the mount failure
is a simple incompatibility.

I'll submit that the probably-not-corrupted errors don't warrant
this much noise, so this patch removes the warning for anything
other than EFSCORRUPTED returns, and replaces the lower-level
XFS_CORRUPTION_ERROR with an xfs_notice().
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

When xfs_readsb() does the very first read of the superblock,
it makes a guess at the length of the buffer, based on the
sector size of the underlying storage.  This may or may
not match the filesystem sector size in sb_sectsize, so
we can't i.e. do a CRC check on it; it might be too short.

In fact, mounting a filesystem with sb_sectsize larger
than the device sector size will cause a mount failure
if CRCs are enabled, because we are checksumming a length
which exceeds the buffer passed to it.

So always read twice; the first time we read with NULL
buffer ops to skip verification; then set the proper
read length, hook up the proper verifier, and give it
another go.

Once we are sure that we've got the right buffer length,
we can also use bp->b_length in the xfs_sb_read_verify,
rather than the less-trusted on-disk sectorsize for
secondary superblocks.  Before this we ran the risk of
passing junk to the crc32c routines, which didn't always
handle extreme values.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

My earlier commit 10e6e65d deserves a layer or two of brown paper
bags.  The logic in that commit means that a CRC failure on the
primary superblock will *never* result in an error return.

Hopefully this fixes it, so that we always return the error
if it's a primary superblock, otherwise only if the filesystem
has CRCs enabled.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

My rework of handling of notification events (namely commit 7053aee2
"fsnotify: do not share events between notification groups") broke
sending of cookies with inotify events. We didn't propagate the value
passed to fsnotify() properly and passed 4 uninitialized bytes to
userspace instead (so it is also an information leak). Sadly I didn't
notice this during my testing because inotify cookies aren't used very
much and LTP inotify tests ignore them.

Fix the problem by passing the cookie value properly.

Fixes: 7053aee2Reported-by: NVegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: NJan Kara <jack@suse.cz>

If start_this_handle() fails then it leads to a use after free of
"handle".
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

When FS-Cache allocates an object, the following sequence of events can
occur:

 -->fscache_alloc_object()
    -->cachefiles_alloc_object() [via cache->ops->alloc_object]
    <--[returns new object]
    -->fscache_attach_object()
    <--[failed]
    -->cachefiles_put_object() [via cache->ops->put_object]
       -->fscache_object_destroy()
          -->fscache_objlist_remove()
             -->rb_erase() to remove the object from fscache_object_list.

resulting in a crash in the rbtree code.

The problem is that the object is only added to fscache_object_list on
the success path of fscache_attach_object() where it calls
fscache_objlist_add().

So if fscache_attach_object() fails, the object won't have been added to
the objlist rbtree.  We do, however, unconditionally try to remove the
object from the tree.

Thanks to NeilBrown for finding this and suggesting this solution.
Reported-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: N(a customer of) NeilBrown <neilb@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This has been this way for years, and every time I stumble across it I
lose my lunch.  After coming across it for the nth time in the Coverity
results, I had to overcome the bystander effect and do something about
it.

This ignores the 79 column limit in favor of making it look like C
instead of gibberish.

The correct thing to do here would be to lose some of the indentation by
breaking this function up into several smaller ones.  I might do that at
some point if I have the stomach to look at this again.

(Also some of those overlong ternary operations would likely be more
readable as regular if's)
Signed-off-by: NDave Jones <davej@fedoraproject.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If directory is fragmented, readdir() read its dirfrags one by one.
After reading all dirfrags, the corresponding dentries are sorted in
(frag_t, off) order in the dcache. If dentries of a directory are all
cached, __dcache_readdir() can use the cached dentries to satisfy
readdir syscall. But when checking if a given dentry is after the
position of readdir, __dcache_readdir() compares numerical value of
frag_t directly. This is wrong, it should use ceph_frag_compare().
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>

Make the 'acl' option dependent on having ACL support compiled in.  Make
the 'noacl' option work even without it so that one can always ask it to
be off and not error out on mount when it is not supported.
Signed-off-by: NGuangliang Zhao <lucienchao@gmail.com>
Signed-off-by: NSage Weil <sage@inktank.com>

Signed-off-by: NGuangliang Zhao <lucienchao@gmail.com>
Reviewed-by: NAlex Elder <elder@linaro.org>
Signed-off-by: NSage Weil <sage@inktank.com>

Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>

If acl is equivalent to file mode permission bits, ceph_set_acl()
needs to remove any existing acl xattr. Use __ceph_setxattr() to
handle both setting and removing acl xattr cases, it doesn't return
-ENODATA when there is no acl xattr.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>

Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>