Only for ceph_sync_write, the osd can return EOLDSNAPC.so move the
related codes after the call ceph_sync_write.
Signed-off-by: NJianpeng Ma <majianpeng@gmail.com>
Reviewed-by: NSage Weil <sage@inktank.com>

remove_session_caps() uses iterate_session_caps() to remove caps,
but iterate_session_caps() skips inodes that are being deleted.
So session->s_nr_caps can be non-zero after iterate_session_caps()
return.

We can fix the issue by waiting until deletions are complete.
__wait_on_freeing_inode() is designed for the job, but it is not
exported, so we use lookup inode function to access it.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>

Func ceph_calc_ceph_pg maybe failed.So add check for returned value.
Signed-off-by: NJianpeng Ma <majianpeng@gmail.com>
Reviewed-by: NSage Weil <sage@inktank.com>
Signed-off-by: NSage Weil <sage@inktank.com>

Sending reads and writes through the sync read/write paths bypasses the
page cache, which is not expected or generally a good idea.  Removing
the write check is safe as there is a conditional vfs_fsync_range() later
in ceph_aio_write that already checks for the same flag (via
IS_SYNC(inode)).
Signed-off-by: NJianpeng Ma <majianpeng@gmail.com>
Reviewed-by: NSage Weil <sage@inktank.com>

We pass in a u64 value for "len" and then immediately truncate away the
upper 32 bits.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NSage Weil <sage@inktank.com>
Reviewed-by: NAlex Elder <alex.elder@linaro.org>

The MDS uses caps message to notify clients about deleted inode.
when receiving a such message, invalidate any alias of the inode.
This makes the kernel release the inode ASAP.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

To write data, the writer first acquires the i_mutex, then try getting
caps. The writer may sleep while holding the i_mutex. If the MDS revokes
Fb cap in this case, vmtruncate work can't do its job because i_mutex
is locked. We should wake up the writer and let it truncate the pages.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

To handle "link" request, the MDS need to xlock inode's linklock,
which requires revoking any CAP_LINK_SHARED.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

When register_session() is given an out-of-range argument for mds,
ceph_mdsmap_get_addr() will return a null pointer, which would be given to
ceph_con_open() & be dereferenced, causing a kernel oops. This fixes bug #4685
in the Ceph bug tracker <http://tracker.ceph.com/issues/4685>.
Signed-off-by: NNathaniel Yazdani <n1ght.4nd.d4y@gmail.com>
Reviewed-by: NSage Weil <sage@inktank.com>

CC: stable@vger.kernel.org
Signed-off-by: NJianpeng Ma <majianpeng@gmail.com>
Reviewed-by: NSage Weil <sage@inktank.com>

If we receive new caps from the auth MDS and the non-auth MDS is
revoking the newly issued caps, we should release the caps from
the non-auth MDS. The scenario is filelock's state changes from
SYNC to LOCK. Non-auth MDS revokes Fc cap, the client gets Fc cap
from the auth MDS at the same time.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

If caps are been revoking by the auth MDS, don't consider them as
issued even they are still issued by non-auth MDS. The non-auth
MDS should also be revoking/exporting these caps, the client just
hasn't received the cap revoke/export message.

The race I encountered is: When caps are exporting to new MDS, the
client receives cap import message and cap revoke message from the
new MDS, then receives cap export message from the old MDS. When
the client receives cap revoke message from the new MDS, the revoking
caps are still issued by the old MDS, so the client does nothing.
Later when the cap export message is received, the client removes
the caps issued by the old MDS. (Another way to fix the race is
calling ceph_check_caps() in handle_cap_export())
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

The locking order for pending vmtruncate is wrong, it can lead to
following race:

        write                  wmtruncate work
------------------------    ----------------------
lock i_mutex
check i_truncate_pending   check i_truncate_pending
truncate_inode_pages()     lock i_mutex (blocked)
copy data to page cache
unlock i_mutex
                           truncate_inode_pages()

The fix is take i_mutex before calling __ceph_do_pending_vmtruncate()

Fixes: http://tracker.ceph.com/issues/5453Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

when mounting ceph with a dev name that starts with a slash, ceph
would attempt to access the character before that slash. Since we
don't actually own that byte of memory, we would trigger an
invalid access:

[   43.499934] BUG: unable to handle kernel paging request at ffff880fa3a97fff
[   43.500984] IP: [<ffffffff818f3884>] parse_mount_options+0x1a4/0x300
[   43.501491] PGD 743b067 PUD 10283c4067 PMD 10282a6067 PTE 8000000fa3a97060
[   43.502301] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[   43.503006] Dumping ftrace buffer:
[   43.503596]    (ftrace buffer empty)
[   43.504046] CPU: 0 PID: 10879 Comm: mount Tainted: G        W    3.10.0-sasha #1129
[   43.504851] task: ffff880fa625b000 ti: ffff880fa3412000 task.ti: ffff880fa3412000
[   43.505608] RIP: 0010:[<ffffffff818f3884>]  [<ffffffff818f3884>] parse_mount_options$
[   43.506552] RSP: 0018:ffff880fa3413d08  EFLAGS: 00010286
[   43.507133] RAX: ffff880fa3a98000 RBX: ffff880fa3a98000 RCX: 0000000000000000
[   43.507893] RDX: ffff880fa3a98001 RSI: 000000000000002f RDI: ffff880fa3a98000
[   43.508610] RBP: ffff880fa3413d58 R08: 0000000000001f99 R09: ffff880fa3fe64c0
[   43.509426] R10: ffff880fa3413d98 R11: ffff880fa38710d8 R12: ffff880fa3413da0
[   43.509792] R13: ffff880fa3a97fff R14: 0000000000000000 R15: ffff880fa3413d90
[   43.509792] FS:  00007fa9c48757e0(0000) GS:ffff880fd2600000(0000) knlGS:000000000000$
[   43.509792] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[   43.509792] CR2: ffff880fa3a97fff CR3: 0000000fa3bb9000 CR4: 00000000000006b0
[   43.509792] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   43.509792] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[   43.509792] Stack:
[   43.509792]  0000e5180000000e ffffffff85ca1900 ffff880fa38710d8 ffff880fa3413d98
[   43.509792]  0000000000000120 0000000000000000 ffff880fa3a98000 0000000000000000
[   43.509792]  ffffffff85cf32a0 0000000000000000 ffff880fa3413dc8 ffffffff818f3c72
[   43.509792] Call Trace:
[   43.509792]  [<ffffffff818f3c72>] ceph_mount+0xa2/0x390
[   43.509792]  [<ffffffff81226314>] ? pcpu_alloc+0x334/0x3c0
[   43.509792]  [<ffffffff81282f8d>] mount_fs+0x8d/0x1a0
[   43.509792]  [<ffffffff812263d0>] ? __alloc_percpu+0x10/0x20
[   43.509792]  [<ffffffff8129f799>] vfs_kern_mount+0x79/0x100
[   43.509792]  [<ffffffff812a224d>] do_new_mount+0xcd/0x1c0
[   43.509792]  [<ffffffff812a2e8d>] do_mount+0x15d/0x210
[   43.509792]  [<ffffffff81220e55>] ? strndup_user+0x45/0x60
[   43.509792]  [<ffffffff812a2fdd>] SyS_mount+0x9d/0xe0
[   43.509792]  [<ffffffff83fd816c>] tracesys+0xdd/0xe2
[   43.509792] Code: 4c 8b 5d c0 74 0a 48 8d 50 01 49 89 14 24 eb 17 31 c0 48 83 c9 ff $
[   43.509792] RIP  [<ffffffff818f3884>] parse_mount_options+0x1a4/0x300
[   43.509792]  RSP <ffff880fa3413d08>
[   43.509792] CR2: ffff880fa3a97fff
[   43.509792] ---[ end trace 22469cd81e93af51 ]---
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Reviewed-by: NSage Weil <sage@inktan.com>

Drop ignored return value.  Fix allocation failure case to not leak.
Signed-off-by: NJianpeng Ma <majianpeng@gmail.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Signed-off-by: NJianpeng Ma <majianpeng@gmail.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Either in vfs_write or io_submit,it call file_start/end_write.
The different between file_start/end_write and sb_start/end_write is
file_ only handle regular file.But i think in ceph_aio_write,it only
for regular file.
Signed-off-by: NJianpeng Ma <majianpeng@gmail.com>
Acked-by: NYan, Zheng <zheng.z.yan@intel.com>

Signed-off-by: NJianpeng Ma <majianpeng@gmail.com>
Reviewed-by: NSage Weil <sage@inktank.com>

[ 1121.231883] BUG: sleeping function called from invalid context at kernel/rwsem.c:20
[ 1121.231935] in_atomic(): 1, irqs_disabled(): 0, pid: 9831, name: mv
[ 1121.231971] 1 lock held by mv/9831:
[ 1121.231973]  #0:  (&(&ci->i_ceph_lock)->rlock){+.+...},at:[<ffffffffa02bbd38>] ceph_getxattr+0x58/0x1d0 [ceph]
[ 1121.231998] CPU: 3 PID: 9831 Comm: mv Not tainted 3.10.0-rc6+ #215
[ 1121.232000] Hardware name: To Be Filled By O.E.M. To Be Filled By
O.E.M./To be filled by O.E.M., BIOS 080015  11/09/2011
[ 1121.232027]  ffff88006d355a80 ffff880092f69ce0 ffffffff8168348c ffff880092f69cf8
[ 1121.232045]  ffffffff81070435 ffff88006d355a20 ffff880092f69d20 ffffffff816899ba
[ 1121.232052]  0000000300000004 ffff8800b76911d0 ffff88006d355a20 ffff880092f69d68
[ 1121.232056] Call Trace:
[ 1121.232062]  [<ffffffff8168348c>] dump_stack+0x19/0x1b
[ 1121.232067]  [<ffffffff81070435>] __might_sleep+0xe5/0x110
[ 1121.232071]  [<ffffffff816899ba>] down_read+0x2a/0x98
[ 1121.232080]  [<ffffffffa02baf70>] ceph_vxattrcb_layout+0x60/0xf0 [ceph]
[ 1121.232088]  [<ffffffffa02bbd7f>] ceph_getxattr+0x9f/0x1d0 [ceph]
[ 1121.232093]  [<ffffffff81188d28>] vfs_getxattr+0xa8/0xd0
[ 1121.232097]  [<ffffffff8118900b>] getxattr+0xab/0x1c0
[ 1121.232100]  [<ffffffff811704f2>] ? final_putname+0x22/0x50
[ 1121.232104]  [<ffffffff81155f80>] ? kmem_cache_free+0xb0/0x260
[ 1121.232107]  [<ffffffff811704f2>] ? final_putname+0x22/0x50
[ 1121.232110]  [<ffffffff8109e63d>] ? trace_hardirqs_on+0xd/0x10
[ 1121.232114]  [<ffffffff816957a7>] ? sysret_check+0x1b/0x56
[ 1121.232120]  [<ffffffff81189c9c>] SyS_fgetxattr+0x6c/0xc0
[ 1121.232125]  [<ffffffff81695782>] system_call_fastpath+0x16/0x1b
[ 1121.232129] BUG: scheduling while atomic: mv/9831/0x10000002
[ 1121.232154] 1 lock held by mv/9831:
[ 1121.232156]  #0:  (&(&ci->i_ceph_lock)->rlock){+.+...}, at:
[<ffffffffa02bbd38>] ceph_getxattr+0x58/0x1d0 [ceph]

I think move the ci->i_ceph_lock down is safe because we can't free
ceph_inode_info at there.

CC: stable@vger.kernel.org  # 3.8+
Signed-off-by: NJianpeng Ma <majianpeng@gmail.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

We may receive old request reply from the exporter MDS after receiving
the importer MDS' cap import message.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

The client can receive truncate request from MDS at any time.
So the page writeback code need to get i_size, truncate_seq and
truncate_size atomically
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

ceph_encode_inode_release() can race with ceph_open() and release
caps wanted by open files. So it should call __ceph_caps_wanted()
to get the wanted caps.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

I introduced a new temporary variable "info" instead of
"m->m_info[mds]".  Also I reversed the if condition and pulled
everything in one indent level.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

This patch makes the following improvements to the error handling
in the ceph_mdsmap_decode function:

- Add a NULL check for return value from kcalloc
- Make use of the variable err
Signed-off-by: NEmil Goode <emilgoode@gmail.com>
Signed-off-by: NSage Weil <sage@inktank.com>

Signed-off-by: NJim Schutt <jaschut@sandia.gov>
Reviewed-by: NAlex Elder <elder@inktank.com>

Ceph's encode_caps_cb() worked hard to not call __page_cache_alloc()
while holding a lock, but it's spoiled because ceph_pagelist_addpage()
always calls kmap(), which might sleep.  Here's the result:

[13439.295457] ceph: mds0 reconnect start
[13439.300572] BUG: sleeping function called from invalid context at include/linux/highmem.h:58
[13439.309243] in_atomic(): 1, irqs_disabled(): 0, pid: 12059, name: kworker/1:1
    . . .
[13439.376225] Call Trace:
[13439.378757]  [<ffffffff81076f4c>] __might_sleep+0xfc/0x110
[13439.384353]  [<ffffffffa03f4ce0>] ceph_pagelist_append+0x120/0x1b0 [libceph]
[13439.391491]  [<ffffffffa0448fe9>] ceph_encode_locks+0x89/0x190 [ceph]
[13439.398035]  [<ffffffff814ee849>] ? _raw_spin_lock+0x49/0x50
[13439.403775]  [<ffffffff811cadf5>] ? lock_flocks+0x15/0x20
[13439.409277]  [<ffffffffa045e2af>] encode_caps_cb+0x41f/0x4a0 [ceph]
[13439.415622]  [<ffffffff81196748>] ? igrab+0x28/0x70
[13439.420610]  [<ffffffffa045e9f8>] ? iterate_session_caps+0xe8/0x250 [ceph]
[13439.427584]  [<ffffffffa045ea25>] iterate_session_caps+0x115/0x250 [ceph]
[13439.434499]  [<ffffffffa045de90>] ? set_request_path_attr+0x2d0/0x2d0 [ceph]
[13439.441646]  [<ffffffffa0462888>] send_mds_reconnect+0x238/0x450 [ceph]
[13439.448363]  [<ffffffffa0464542>] ? ceph_mdsmap_decode+0x5e2/0x770 [ceph]
[13439.455250]  [<ffffffffa0462e42>] check_new_map+0x352/0x500 [ceph]
[13439.461534]  [<ffffffffa04631ad>] ceph_mdsc_handle_map+0x1bd/0x260 [ceph]
[13439.468432]  [<ffffffff814ebc7e>] ? mutex_unlock+0xe/0x10
[13439.473934]  [<ffffffffa043c612>] extra_mon_dispatch+0x22/0x30 [ceph]
[13439.480464]  [<ffffffffa03f6c2c>] dispatch+0xbc/0x110 [libceph]
[13439.486492]  [<ffffffffa03eec3d>] process_message+0x1ad/0x1d0 [libceph]
[13439.493190]  [<ffffffffa03f1498>] ? read_partial_message+0x3e8/0x520 [libceph]
    . . .
[13439.587132] ceph: mds0 reconnect success
[13490.720032] ceph: mds0 caps stale
[13501.235257] ceph: mds0 recovery completed
[13501.300419] ceph: mds0 caps renewed

Fix it up by encoding locks into a buffer first, and when the number
of encoded locks is stable, copy that into a ceph_pagelist.

[elder@inktank.com: abbreviated the stack info a bit.]

Cc: stable@vger.kernel.org # 3.4+
Signed-off-by: NJim Schutt <jaschut@sandia.gov>
Reviewed-by: NAlex Elder <elder@inktank.com>

In his review, Alex Elder mentioned that he hadn't checked that
num_fcntl_locks and num_flock_locks were properly decoded on the
server side, from a le32 over-the-wire type to a cpu type.
I checked, and AFAICS it is done; those interested can consult
    Locker::_do_cap_update()
in src/mds/Locker.cc and src/include/encoding.h in the Ceph server
code (git://github.com/ceph/ceph).

I also checked the server side for flock_len decoding, and I believe
that also happens correctly, by virtue of having been declared
__le32 in struct ceph_mds_cap_reconnect, in src/include/ceph_fs.h.

Cc: stable@vger.kernel.org # 3.4+
Signed-off-by: NJim Schutt <jaschut@sandia.gov>
Reviewed-by: NAlex Elder <elder@inktank.com>

Faster kernel compiles by way of fewer unnecessary includes.

[akpm@linux-foundation.org: fix fallout]
[akpm@linux-foundation.org: fix build]
Signed-off-by: NKent Overstreet <koverstreet@google.com>
Cc: Zach Brown <zab@redhat.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Reviewed-by: N"Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that we have a library routine to create snap contexts, use it.

This is part of:
    http://tracker.ceph.com/issues/4857Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

In the incremental move toward supporting distinct data items in an
osd request some of the functions had "write_request" parameters to
indicate, basically, whether the data belonged to in_data or the
out_data.  Now that we maintain the data fields in the op structure
there is no need to indicate the direction, so get rid of the
"write_request" parameters.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Fix printk format warnings by using %zd for 'ssize_t' variables:

fs/ceph/file.c:751:2: warning: format '%ld' expects argument of type 'long int', but argument 11 has type 'ssize_t' [-Wformat]
fs/ceph/file.c:762:2: warning: format '%ld' expects argument of type 'long int', but argument 11 has type 'ssize_t' [-Wformat]
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc:	ceph-devel@vger.kernel.org
Signed-off-by: NSage Weil <sage@inktank.com>

ceph_writepages_start() reads inode->i_size in two places. It can get
different values between successive read, because truncate can change
inode->i_size at any time. The race can lead to mismatch between data
length of osd request and pages marked as writeback. When osd request
finishes, it clear writeback page according to its data length. So
some pages can be left in writeback state forever. The fix is only
read inode->i_size once, save its value to a local variable and use
the local variable when i_size is needed.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

copy write checks in __generic_file_aio_write to ceph_aio_write.
To make these checks cover sync write path.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

There is deadlock as illustrated bellow. The fix is taking i_mutex
before getting Fw cap reference.

      write                    truncate                 MDS
---------------------     --------------------      --------------
get Fw cap
                          lock i_mutex
lock i_mutex (blocked)
                          request setattr.size  ->
                                                <-   revoke Fw cap
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

An osd request currently has two callbacks.  They inform the
initiator of the request when we've received confirmation for the
target osd that a request was received, and when the osd indicates
all changes described by the request are durable.

The only time the second callback is used is in the ceph file system
for a synchronous write.  There's a race that makes some handling of
this case unsafe.  This patch addresses this problem.  The error
handling for this callback is also kind of gross, and this patch
changes that as well.

In ceph_sync_write(), if a safe callback is requested we want to add
the request on the ceph inode's unsafe items list.  Because items on
this list must have their tid set (by ceph_osd_start_request()), the
request added *after* the call to that function returns.  The
problem with this is that there's a race between starting the
request and adding it to the unsafe items list; the request may
already be complete before ceph_sync_write() even begins to put it
on the list.

To address this, we change the way the "safe" callback is used.
Rather than just calling it when the request is "safe", we use it to
notify the initiator the bounds (start and end) of the period during
which the request is *unsafe*.  So the initiator gets notified just
before the request gets sent to the osd (when it is "unsafe"), and
again when it's known the results are durable (it's no longer
unsafe).  The first call will get made in __send_request(), just
before the request message gets sent to the messenger for the first
time.  That function is only called by __send_queued(), which is
always called with the osd client's request mutex held.

We then have this callback function insert the request on the ceph
inode's unsafe list when we're told the request is unsafe.  This
will avoid the race because this call will be made under protection
of the osd client's request mutex.  It also nicely groups the setup
and cleanup of the state associated with managing unsafe requests.

The name of the "safe" callback field is changed to "unsafe" to
better reflect its new purpose.  It has a Boolean "unsafe" parameter
to indicate whether the request is becoming unsafe or is now safe.
Because the "msg" parameter wasn't used, we drop that.

This resolves the original problem reportedin:
    http://tracker.ceph.com/issues/4706Reported-by: NYan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

In ceph_sync_write(), if a safe callback is supplied with a request,
and an error is returned by ceph_osdc_wait_request(), a block of
code is executed to remove the request from the unsafe writes list
and drop references to capabilities acquired just prior to a call to
ceph_osdc_wait_request().

The only function used for this callback is sync_write_commit(),
and it does *exactly* what that block of error handling code does.

Now in ceph_osdc_wait_request(), if an error occurs (due to an
interupt during a wait_for_completion_interruptible() call),
complete_request() gets called, and that calls the request's
safe_callback method if it's defined.

So this means that this cleanup activity gets called twice in this
case, which is erroneous (and in fact leads to a crash).

Fix this by just letting the osd client handle the cleanup in
the event of an interrupt.

This resolves one problem mentioned in:
    http://tracker.ceph.com/issues/4706Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NYan, Zheng <zheng.z.yan@intel.com>

add getattr/setattr and xattrs related methods.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NGreg Farnum <greg@inktank.com>