litmus-rt.git/fs/ocfs2/cluster, branch master

Revert "ocfs2: incorrect check for debugfs returns"

2015-04-21T16:17:28+00:00

This reverts commit e2ac55b6a8e337fac7cc59c6f452caac92ab5ee6.

Huang Ying reports that this causes a hang at boot with debugfs disabled.

It is true that the debugfs error checks are kind of confusing, and this
code certainly merits more cleanup and thinking about it, but there's
something wrong with the trivial "check not just for NULL, but for error
pointers too" patch.

Yes, with debugfs disabled, we will end up setting the o2hb_debug_dir
pointer variable to an error pointer (-ENODEV), and then continue as if
everything was fine.  But since debugfs is disabled, all the _users_ of
that pointer end up being compiled away, so even though the pointer can
not be dereferenced, that's still fine.

So it's confusing and somewhat questionable, but the "more correct"
error checks end up causing more trouble than they fix.

Reported-by: Huang Ying 
Acked-by: Andrew Morton 
Acked-by: Chengyu Song 
Signed-off-by: Linus Torvalds

ocfs2: make mlog_errno return the errno

2015-04-14T23:48:58+00:00

ocfs2 does

        mlog_errno(v);
        return v;

in many places.  Change mlog_errno() so we can do

        return mlog_errno(v);

For some weird reason this patch reduces the size of ocfs2 by 6k:

  akpm3:/usr/src/25> size fs/ocfs2/ocfs2.ko
     text    data     bss     dec     hex filename
  1146613   82767  832192 2061572  1f7504 fs/ocfs2/ocfs2.ko-before
  1140857   82767  832192 2055816  1f5e88 fs/ocfs2/ocfs2.ko-after

[dan.carpenter@oracle.com: double evaluation concerns in mlog_errno()]
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: alex chen 
Signed-off-by: Dan Carpenter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ocfs2: incorrect check for debugfs returns

2015-04-14T23:48:58+00:00

debugfs_create_dir and debugfs_create_file may return -ENODEV when debugfs
is not configured, so the return value should be checked against
ERROR_VALUE as well, otherwise the later dereference of the dentry pointer
would crash the kernel.

This patch tries to solve this problem by fixing certain checks. However,
I have that found other call sites are protected by #ifdef CONFIG_DEBUG_FS.
In current implementation, if CONFIG_DEBUG_FS is defined, then the above
two functions will never return any ERROR_VALUE. So another possibility
to fix this is to surround all the buggy checks/functions with the same
#ifdef CONFIG_DEBUG_FS. But I'm not sure if this would break any functionality,
as only OCFS2_FS_STATS declares dependency on DEBUG_FS.

Signed-off-by: Chengyu Song 
Cc: Mark Fasheh 
Cc: Joel Becker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ocfs2: o2net: silence uninitialized variable warning

2015-02-10T22:30:29+00:00

Smatch complains that, if o2net_tx_can_proceed() returns false, then "sc"
and "ret" are uninialized or maybe we are re-using the data from previous
iteration.  I do not know if we can hit this bug in real life but checking
the return value is harmless and we may as well silence the static checker
warning.

Signed-off-by: Dan Carpenter 
Cc: Mark Fasheh 
Cc: Joel Becker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ocfs2: fix wrong comment

2015-02-10T22:30:28+00:00

O2NET_CONN_IDLE_DELAY is not defined, connection attempts will not be
canceled due to timeout.

Signed-off-by: Junxiao Bi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ocfs2: o2net: fix connect expired

2014-12-11T01:41:03+00:00

Set nn_persistent_error to -ENOTCONN will stop reconnect since the
"stop" condition in o2net_start_connect() will be true.

    stop = (nn->nn_sc ||
                (nn->nn_persistent_error &&
                (nn->nn_persistent_error != -ENOTCONN || timeout == 0)));

This will make connection never be established if the first connection
request is lost.

Set nn_persistent_error to 0 when connect expired to fix this.  With
this changes, dlm will not be waken up when connect expired, this is OK
since dlm depends on network, dlm can do nothing in this case if waken
up.  Let it wait there for network recover and connect built again to
continue.

Signed-off-by: Junxiao Bi 
Reviewed-by: Srinivas Eeda 
Cc: Joel Becker 
Cc: Mark Fasheh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ocfs2: report error from o2hb_do_disk_heartbeat() to user

2014-12-11T01:41:03+00:00

Report return value of o2hb_do_disk_heartbeat() as a part of ML_HEARTBEAT
message so that we know whether a heartbeat actually happened or not.
This also makes assigned but otherwise unused 'ret' variable used.

Coverity id: 1227053.

Signed-off-by: Jan Kara 
Cc: Mark Fasheh 
Cc: Joel Becker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fix breakage in o2net_send_tcp_msg()

2014-11-05T20:21:18+00:00

uninitialized msghdr.  Broken in "ocfs2: don't open-code kernel_recvmsg()"
by me ;-/

Cc: stable@vger.kernel.org # 3.15+
Signed-off-by: Al Viro

ocfs2: replace strnicmp with strncasecmp

2014-10-14T00:18:24+00:00

The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp.  The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.

To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.

Signed-off-by: Rasmus Villemoes 
Cc: Mark Fasheh 
Cc: Joel Becker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ocfs2: fix a deadlock while o2net_wq doing direct memory reclaim

2014-10-10T02:25:58+00:00

Fix a deadlock problem caused by direct memory reclaim in o2net_wq.  The
situation is as follows:

1) Receive a connect message from another node, node queues a
   work_struct o2net_listen_work.

2) o2net_wq processes this work and call the following functions:

o2net_wq
-> o2net_accept_one
  -> sock_create_lite
    -> sock_alloc()
      -> kmem_cache_alloc with GFP_KERNEL
        -> ____cache_alloc_node
          ->__alloc_pages_nodemask
            -> do_try_to_free_pages
              -> shrink_slab
                -> evict
                  -> ocfs2_evict_inode
                    -> ocfs2_drop_lock
                      -> dlmunlock
                        -> o2net_send_message_vec

   then o2net_wq wait for the unlock reply from master.

3) tcp layer received the reply, call o2net_data_ready() and queue
   sc_rx_work, waiting o2net_wq to process this work.

4) o2net_wq is a single thread workqueue, it process the work one by
   one.  Right now it is still doing o2net_listen_work and cannot handle
   sc_rx_work.  so we deadlock.

Junxiao Bi's patch "mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set"
(http://ozlabs.org/~akpm/mmots/broken-out/mm-clear-__gfp_fs-when-pf_memalloc_noio-is-set.patch)
clears __GFP_FS in memalloc_noio_flags() besides __GFP_IO.  We use
memalloc_noio_save() to set process flag PF_MEMALLOC_NOIO so that all
allocations done by this process are done as if GFP_NOIO was specified.
We are not reentering filesystem while doing memory reclaim.

Signed-off-by: joyce.xue 
Cc: Junxiao Bi 
Cc: Joel Becker 
Cc: Mark Fasheh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds