GitLab

The authorize reply can be empty, for example when the ticket used to
build the authorizer is too old and TAG_BADAUTHORIZER is returned from
the service.  Calling ->verify_authorizer_reply() results in an attempt
to decrypt and validate (somewhat) random data in au->buf (most likely
the signature block from calc_signature()), which fails and ends up in
con_fault_finish() with !con->auth_retry.  The ticket isn't invalidated
and the connection is retried again and again until a new ticket is
obtained from the monitor:

  libceph: osd2 192.168.122.1:6809 bad authorize reply
  libceph: osd2 192.168.122.1:6809 bad authorize reply
  libceph: osd2 192.168.122.1:6809 bad authorize reply
  libceph: osd2 192.168.122.1:6809 bad authorize reply

Let TAG_BADAUTHORIZER handler kick in and increment con->auth_retry.

Cc: stable@vger.kernel.org
Fixes: 5c056fdc ("libceph: verify authorize reply on connect")
Link: https://tracker.ceph.com/issues/20164

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>

con_fault() can transition the connection into STANDBY right after
ceph_con_keepalive() clears STANDBY in clear_standby():

    libceph user thread               ceph-msgr worker

ceph_con_keepalive()
  mutex_lock(&con->mutex)
  clear_standby(con)
  mutex_unlock(&con->mutex)
                                mutex_lock(&con->mutex)
                                con_fault()
                                  ...
                                  if KEEPALIVE_PENDING isn't set
                                    set state to STANDBY
                                  ...
                                mutex_unlock(&con->mutex)
  set KEEPALIVE_PENDING
  set WRITE_PENDING

This triggers warnings in clear_standby() when either ceph_con_send()
or ceph_con_keepalive() get to clearing STANDBY next time.

I don't see a reason to condition queue_con() call on the previous
value of KEEPALIVE_PENDING, so move the setting of KEEPALIVE_PENDING
into the critical section -- unlike WRITE_PENDING, KEEPALIVE_PENDING
could have been a non-atomic flag.

Reported-by: syzbot+acdeb633f6211ccdf886@syzkaller.appspotmail.com
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Tested-by: Myungho Jung <mhjungk@gmail.com>

Unlike in ceph_tcp_sendpage(), it's a bool.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Prevent do_tcp_sendpages() from calling tcp_push() (at least) once per
page.  Instead, arrange for tcp_push() to be called (at least) once per
data payload.  This results in more MSS-sized packets and fewer packets
overall (5-10% reduction in my tests with typical OSD request sizes).
See commits 2f533844 ("tcp: allow splice() to build full TSO
packets"), 35f9c09f ("tcp: tcp_sendpages() should call tcp_push()
once") and ae62ca7b

 ("tcp: fix MSG_SENDPAGE_NOTLAST logic") for
details.

Here is an example of a packet size histogram for 128K OSD requests
(MSS = 1448, top 5):

Before:

     SIZE    COUNT
     1448   777700
      952   127915
     1200    39238
     1219     9806
       21     5675

After:

     SIZE    COUNT
     1448   897280
       21     6201
     1019     2797
      643     2739
      376     2479

We could do slightly better by explicitly corking the socket but it's
not clear it's worth it.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

sock_no_sendpage() makes the code cleaner.

Also, don't set MSG_EOR.  sendpage doesn't act on MSG_EOR on its own,
it just honors the setting from the preceding sendmsg call by looking
at ->eor in tcp_skb_can_collapse_to().
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

last_piece is for the last piece in the current data item, not in the
entire data payload of the message.  This is harmful for messages with
multiple data items.  On top of that, we don't need to signal the end
of a data payload either because it is always followed by a footer.

We used to signal "more" unconditionally, until commit fe38a2b6
("libceph: start defining message data cursor").  Part of a large
series, it introduced cursor->last_piece and also mistakenly inverted
the hint by passing last_piece for "more".  This was corrected with
commit c2cfa194 ("libceph: Fix ceph_tcp_sendpage()'s more boolean
usage").

As it is, last_piece is not helping at all: because Nagle algorithm is
disabled, for a simple message with two 512-byte data items we end up
emitting three packets: front + first data item, second data item and
footer.  Go back to the original pre-fe38a2b6

 behavior -- a single
packet in most cases.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

skb_can_coalesce() allows coalescing neighboring slab objects into
a single frag:

  return page == skb_frag_page(frag) &&
         off == frag->page_offset + skb_frag_size(frag);

ceph_tcp_sendpage() can be handed slab pages.  One example of this is
XFS: it passes down sector sized slab objects for its metadata I/O.  If
the kernel client is co-located on the OSD node, the skb may go through
loopback and pop on the receive side with the exact same set of frags.
When tcp_recvmsg() attempts to copy out such a frag, hardened usercopy
complains because the size exceeds the object's allocated size:

  usercopy: kernel memory exposure attempt detected from ffff9ba917f20a00 (kmalloc-512) (1024 bytes)

Although skb_can_coalesce() could be taught to return false if the
resulting frag would cross a slab object boundary, we already have
a fallback for non-refcounted pages.  Utilize it for slab pages too.

Cc: stable@vger.kernel.org # 4.8+
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

In the iov_iter struct, separate the iterator type from the iterator
direction and use accessor functions to access them in most places.

Convert a bunch of places to use switch-statements to access them rather
then chains of bitwise-AND statements.  This makes it easier to add further
iterator types.  Also, this can be more efficient as to implement a switch
of small contiguous integers, the compiler can use ~50% fewer compare
instructions than it has to use bitwise-and instructions.

Further, cease passing the iterator type into the iterator setup function.
The iterator function can set that itself.  Only the direction is required.
Signed-off-by: David Howells <dhowells@redhat.com>

Currently message data items are allocated with ceph_msg_data_create()
in setup_request_data() inside send_request().  send_request() has never
been allowed to fail, so each allocation is followed by a BUG_ON:

  data = ceph_msg_data_create(...);
  BUG_ON(!data);

It's been this way since support for multiple message data items was
added in commit 6644ed7b

 ("libceph: make message data be a pointer")
in 3.10.

There is no reason to delay the allocation of message data items until
the last possible moment and we certainly don't need a linked list of
them as they are only ever appended to the end and never erased.  Make
ceph_msg_new2() take max_data_items and adapt the rest of the code.
Reported-by: Jerry Lee <leisurelysw24@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Because send_mds_reconnect() wants to send a message with a pagelist
and pass the ownership to the messenger, ceph_msg_data_add_pagelist()
consumes a ref which is then put in ceph_msg_data_destroy().  This
makes managing pagelists in the OSD client (where they are wrapped in
ceph_osd_data) unnecessarily hard because the handoff only happens in
ceph_osdc_start_request() instead of when the pagelist is passed to
ceph_osd_data_pagelist_init().  I counted several memory leaks on
various error paths.

Fix up ceph_msg_data_add_pagelist() and carry a pagelist ref in
ceph_osd_data.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Avoid scribbling over memory if the received reply/challenge is larger
than the buffer supplied with the authorizer.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>

When a client authenticates with a service, an authorizer is sent with
a nonce to the service (ceph_x_authorize_[ab]) and the service responds
with a mutation of that nonce (ceph_x_authorize_reply).  This lets the
client verify the service is who it says it is but it doesn't protect
against a replay: someone can trivially capture the exchange and reuse
the same authorizer to authenticate themselves.

Allow the service to reject an initial authorizer with a random
challenge (ceph_x_authorize_challenge).  The client then has to respond
with an updated authorizer proving they are able to decrypt the
service's challenge and that the new authorizer was produced for this
specific connection instance.

The accepting side requires this challenge and response unconditionally
if the client side advertises they have CEPHX_V2 feature bit.

This addresses CVE-2018-1128.

Link: http://tracker.ceph.com/issues/24836

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>

Will be used for sending ceph_msg_connect with an updated authorizer,
after the server challenges the initial authorizer.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>

We already copy authorizer_reply_buf and authorizer_reply_buf_len into
ceph_connection.  Factoring out __prepare_write_connect() requires two
more: authorizer_buf and authorizer_buf_len.  Store the pointer to the
handshake in con->auth rather than piling on.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>

ceph_con_keepalive_expired() is the last user of timespec_add() and some
of the last uses of ktime_get_real_ts().  Replacing this with timespec64
based interfaces  lets us remove that deprecated API.

I'm introducing new ceph_encode_timespec64()/ceph_decode_timespec64()
here that take timespec64 structures and convert to/from ceph_timespec,
which is defined to have an unsigned 32-bit tv_sec member. This extends
the range of valid times to year 2106, avoiding the year 2038 overflow.

The ceph file system portion still uses the old functions for inode
timestamps, this will be done separately after the VFS layer is converted.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Avoid a copy into the "skip buffer".
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

All gotos to "more" are conditioned on con->state == OPEN, but the only
thing "more" does is opening the socket if con->state == PREOPEN.  Kill
that label and rename "more_kvec" to "more".
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jason Dillaman <dillaman@redhat.com>

ceph_con_workfn() validates con->state before calling try_read() and
then try_write().  However, try_read() temporarily releases con->mutex,
notably in process_message() and ceph_con_in_msg_alloc(), opening the
window for ceph_con_close() to sneak in, close the connection and
release con->sock.  When try_write() is called on the assumption that
con->state is still valid (i.e. not STANDBY or CLOSED), a NULL sock
gets passed to the networking stack:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
  IP: selinux_socket_sendmsg+0x5/0x20

Make sure con->state is valid at the top of try_write() and add an
explicit BUG_ON for this, similar to try_read().

Cc: stable@vger.kernel.org
Link: https://tracker.ceph.com/issues/23706

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jason Dillaman <dillaman@redhat.com>

Add __init attribution to the functions which are called only once
during initiating/registering operations and deleting unnecessary
symbol exports.
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

rbd needs this for null copyups -- if copyup data is all zeroes, we
want to save some I/O and network bandwidth.  See rbd_obj_issue_copyup()
in the next commit.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>

In preparation for rbd "fancy" striping, introduce ceph_bvec_iter for
working with bio_vec array data buffers.  The wrappers are trivial, but
make it look similar to ceph_bio_iter.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

The reason we clone bios is to be able to give each object request
(and consequently each ceph_osd_data/ceph_msg_data item) its own
pointer to a (list of) bio(s).  The messenger then initializes its
cursor with cloned bio's ->bi_iter, so it knows where to start reading
from/writing to.  That's all the cloned bios are used for: to determine
each object request's starting position in the provided data buffer.

Introduce ceph_bio_iter to do exactly that -- store position within bio
list (i.e. pointer to bio) + position within that bio (i.e. bvec_iter).
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
[idryomov@gmail.com: amended "Older OSDs" comment]
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Reencoding an already reencoded message is a bad idea.  This could
happen on Policy::stateful_server connections (!CEPH_MSG_CONNECT_LOSSY),
such as MDS sessions.

This didn't pop up in testing because currently only OSD requests are
reencoded and OSD sessions are always lossy.

Fixes: 98ad5ebd

 ("libceph: ceph_connection_operations::reencode_message() method")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>

If kmem_cache_zalloc() returns NULL then the INIT_LIST_HEAD(&data->links);
will Oops.  The callers aren't really prepared for NULL returns so it
doesn't make a lot of difference in real life.

Fixes: 5240d9f9

 ("libceph: replace message data pointer with list")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Give upper layers a chance to reencode the message after the connection
is negotiated and ->peer_features is set.  OSD client will use this to
support both luminous and pre-luminous OSDs (in a single cluster): the
former need MOSDOp v8; the latter will continue to be sent MOSDOp v4.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Reflects ceph.git commit ff1959282826ae6acd7134e1b1ede74ffd1cc04a.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

when reopen a connection, use 'reconnect seq' to clean up
messages that have already been received by peer.

Link: http://tracker.ceph.com/issues/18690

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Both callers ignore the returned bool.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>

CURRENT_TIME is not y2038 safe.  The macro will be deleted and all the
references to it will be replaced by ktime_get_* apis.

struct timespec is also not y2038 safe.  Retain timespec for timestamp
representation here as ceph uses it internally everywhere.  These
references will be changed to use struct timespec64 in a separate patch.

The current_fs_time() api is being changed to use vfs struct inode* as
an argument instead of struct super_block*.

Set the new mds client request r_stamp field using ktime_get_real_ts()
instead of using current_fs_time().

Also, since r_stamp is used as mtime on the server, use timespec_trunc()
to truncate the timestamp, using the right granularity from the
superblock.

This api will be transitioned to be y2038 safe along with vfs.

Link: http://lkml.kernel.org/r/1491613030-11599-5-git-send-email-deepa.kernel@gmail.com

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
M:	Ilya Dryomov <idryomov@gmail.com>
M:	"Yan, Zheng" <zyan@redhat.com>
M:	Sage Weil <sage@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sock_alloc_inode() allocates socket+inode and socket_wq with
GFP_KERNEL, which is not allowed on the writeback path:

    Workqueue: ceph-msgr con_work [libceph]
    ffff8810871cb018 0000000000000046 0000000000000000 ffff881085d40000
    0000000000012b00 ffff881025cad428 ffff8810871cbfd8 0000000000012b00
    ffff880102fc1000 ffff881085d40000 ffff8810871cb038 ffff8810871cb148
    Call Trace:
    [<ffffffff816dd629>] schedule+0x29/0x70
    [<ffffffff816e066d>] schedule_timeout+0x1bd/0x200
    [<ffffffff81093ffc>] ? ttwu_do_wakeup+0x2c/0x120
    [<ffffffff81094266>] ? ttwu_do_activate.constprop.135+0x66/0x70
    [<ffffffff816deb5f>] wait_for_completion+0xbf/0x180
    [<ffffffff81097cd0>] ? try_to_wake_up+0x390/0x390
    [<ffffffff81086335>] flush_work+0x165/0x250
    [<ffffffff81082940>] ? worker_detach_from_pool+0xd0/0xd0
    [<ffffffffa03b65b1>] xlog_cil_force_lsn+0x81/0x200 [xfs]
    [<ffffffff816d6b42>] ? __slab_free+0xee/0x234
    [<ffffffffa03b4b1d>] _xfs_log_force_lsn+0x4d/0x2c0 [xfs]
    [<ffffffff811adc1e>] ? lookup_page_cgroup_used+0xe/0x30
    [<ffffffffa039a723>] ? xfs_reclaim_inode+0xa3/0x330 [xfs]
    [<ffffffffa03b4dcf>] xfs_log_force_lsn+0x3f/0xf0 [xfs]
    [<ffffffffa039a723>] ? xfs_reclaim_inode+0xa3/0x330 [xfs]
    [<ffffffffa03a62c6>] xfs_iunpin_wait+0xc6/0x1a0 [xfs]
    [<ffffffff810aa250>] ? wake_atomic_t_function+0x40/0x40
    [<ffffffffa039a723>] xfs_reclaim_inode+0xa3/0x330 [xfs]
    [<ffffffffa039ac07>] xfs_reclaim_inodes_ag+0x257/0x3d0 [xfs]
    [<ffffffffa039bb13>] xfs_reclaim_inodes_nr+0x33/0x40 [xfs]
    [<ffffffffa03ab745>] xfs_fs_free_cached_objects+0x15/0x20 [xfs]
    [<ffffffff811c0c18>] super_cache_scan+0x178/0x180
    [<ffffffff8115912e>] shrink_slab_node+0x14e/0x340
    [<ffffffff811afc3b>] ? mem_cgroup_iter+0x16b/0x450
    [<ffffffff8115af70>] shrink_slab+0x100/0x140
    [<ffffffff8115e425>] do_try_to_free_pages+0x335/0x490
    [<ffffffff8115e7f9>] try_to_free_pages+0xb9/0x1f0
    [<ffffffff816d56e4>] ? __alloc_pages_direct_compact+0x69/0x1be
    [<ffffffff81150cba>] __alloc_pages_nodemask+0x69a/0xb40
    [<ffffffff8119743e>] alloc_pages_current+0x9e/0x110
    [<ffffffff811a0ac5>] new_slab+0x2c5/0x390
    [<ffffffff816d71c4>] __slab_alloc+0x33b/0x459
    [<ffffffff815b906d>] ? sock_alloc_inode+0x2d/0xd0
    [<ffffffff8164bda1>] ? inet_sendmsg+0x71/0xc0
    [<ffffffff815b906d>] ? sock_alloc_inode+0x2d/0xd0
    [<ffffffff811a21f2>] kmem_cache_alloc+0x1a2/0x1b0
    [<ffffffff815b906d>] sock_alloc_inode+0x2d/0xd0
    [<ffffffff811d8566>] alloc_inode+0x26/0xa0
    [<ffffffff811da04a>] new_inode_pseudo+0x1a/0x70
    [<ffffffff815b933e>] sock_alloc+0x1e/0x80
    [<ffffffff815ba855>] __sock_create+0x95/0x220
    [<ffffffff815baa04>] sock_create_kern+0x24/0x30
    [<ffffffffa04794d9>] con_work+0xef9/0x2050 [libceph]
    [<ffffffffa04aa9ec>] ? rbd_img_request_submit+0x4c/0x60 [rbd]
    [<ffffffff81084c19>] process_one_work+0x159/0x4f0
    [<ffffffff8108561b>] worker_thread+0x11b/0x530
    [<ffffffff81085500>] ? create_worker+0x1d0/0x1d0
    [<ffffffff8108b6f9>] kthread+0xc9/0xe0
    [<ffffffff8108b630>] ? flush_kthread_worker+0x90/0x90
    [<ffffffff816e1b98>] ret_from_fork+0x58/0x90
    [<ffffffff8108b630>] ? flush_kthread_worker+0x90/0x90

Use memalloc_noio_{save,restore}() to temporarily force GFP_NOIO here.

Cc: stable@vger.kernel.org # 3.10+, needs backporting
Link: http://tracker.ceph.com/issues/19309

Reported-by: Sergey Jerusalimov <wintchester@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>

Since we need to change the implementation, stop exposing internals.

Provide kref_read() to read the current reference count; typically
used for debug messages.

Kills two anti-patterns:

	atomic_read(&kref->refcount)
	kref->refcount.counter
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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

... and use ITER_BVEC instead of playing with kmap()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

->get_authorizer(), ->verify_authorizer_reply(), ->sign_message() and
->check_message_signature() shouldn't be doing anything with or on the
connection (like closing it or sending messages).
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>

The length of the reply is protocol-dependent - for cephx it's
ceph_x_authorize_reply.  Nothing sensible can be passed from the
messenger layer anyway.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>

After sending an authorizer (ceph_x_authorize_a + ceph_x_authorize_b),
the client gets back a ceph_x_authorize_reply, which it is supposed to
verify to ensure the authenticity and protect against replay attacks.
The code for doing this is there (ceph_x_verify_authorizer_reply(),
ceph_auth_verify_authorizer_reply() + plumbing), but it is never
invoked by the the messenger.

AFAICT this goes back to 2009, when ceph authentication protocols
support was added to the kernel client in 4e7a5dcd

 ("ceph:
negotiate authentication protocol; implement AUTH_NONE protocol").

The second param of ceph_connection_operations::verify_authorizer_reply
is unused all the way down.  Pass 0 to facilitate backporting, and kill
it in the next commit.

Cc: stable@vger.kernel.org
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use KMEM_CACHE() instead of kmem_cache_create() to simplify the code.
Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>