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  1. 19 Jul, 2014 4 commits
  3. 18 Jul, 2014 12 commits
  5. 17 Jul, 2014 11 commits
  7. 16 Jul, 2014 8 commits
  9. 15 Jul, 2014 5 commits
    • Martin Lau's avatar
      ring-buffer: Fix polling on trace_pipe · 97b8ee84
      Martin Lau authored 
      ring_buffer_poll_wait() should always put the poll_table to its wait_queue
even there is immediate data available.  Otherwise, the following epoll and
read sequence will eventually hang forever:

1. Put some data to make the trace_pipe ring_buffer read ready first
2. epoll_ctl(efd, EPOLL_CTL_ADD, trace_pipe_fd, ee)
3. epoll_wait()
4. read(trace_pipe_fd) till EAGAIN
5. Add some more data to the trace_pipe ring_buffer
6. epoll_wait() -> this epoll_wait() will block forever

~ During the epoll_ctl(efd, EPOLL_CTL_ADD,...) call in step 2,
  ring_buffer_poll_wait() returns immediately without adding poll_table,
  which has poll_table->_qproc pointing to ep_poll_callback(), to its
  wait_queue.
~ During the epoll_wait() call in step 3 and step 6,
  ring_buffer_poll_wait() cannot add ep_poll_callback() to its wait_queue
  because the poll_table->_qproc is NULL and it is how epoll works.
~ When there is new data available in step 6, ring_buffer does not know
  it has to call ep_poll_callback() because it is not in its wait queue.
  Hence, block forever.

Other poll implementation seems to call poll_wait() unconditionally as the very
first thing to do.  For example, tcp_poll() in tcp.c.

Link: http://lkml.kernel.org/p/20140610060637.GA14045@devbig242.prn2.facebook.com

Cc: stable@vger.kernel.org # 2.6.27
Fixes: 2a2cc8f7 "ftrace: allow the event pipe to be polled"
Reviewed-by: default avatarChris Mason <clm@fb.com>
Signed-off-by: default avatarMartin Lau <kafai@fb.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      97b8ee84
    • Niu Yawei's avatar
      quota: missing lock in dqcache_shrink_scan() · d68aab6b
      Niu Yawei authored 
      Commit 1ab6c499 (fs: convert fs shrinkers to new scan/count API)
accidentally removed locking from quota shrinker. Fix it -
dqcache_shrink_scan() should use dq_list_lock to protect the
scan on free_dquots list.

CC: stable@vger.kernel.org
Fixes: 1ab6c499Signed-off-by: default avatarNiu Yawei <yawei.niu@intel.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
      d68aab6b
    • Mike Snitzer's avatar
      dm cache metadata: do not allow the data block size to change · 048e5a07
      Mike Snitzer authored 
      The block size for the dm-cache's data device must remained fixed for
the life of the cache.  Disallow any attempt to change the cache's data
block size.
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Acked-by: default avatarJoe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org
      048e5a07
    • Mike Snitzer's avatar
      dm thin metadata: do not allow the data block size to change · 9aec8629
      Mike Snitzer authored 
      The block size for the thin-pool's data device must remained fixed for
the life of the thin-pool.  Disallow any attempt to change the
thin-pool's data block size.

It should be noted that attempting to change the data block size via
thin-pool table reload will be ignored as a side-effect of the thin-pool
handover that the thin-pool target does during thin-pool table reload.

Here is an example outcome of attempting to load a thin-pool table that
reduced the thin-pool's data block size from 1024K to 512K.

Before:
kernel: device-mapper: thin: 253:4: growing the data device from 204800 to 409600 blocks

After:
kernel: device-mapper: thin metadata: changing the data block size (from 2048 to 1024) is not supported
kernel: device-mapper: table: 253:4: thin-pool: Error creating metadata object
kernel: device-mapper: ioctl: error adding target to table
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Acked-by: default avatarJoe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org
      9aec8629
    • zhangwei(Jovi)'s avatar
      tracing: Add TRACE_ITER_PRINTK flag check in __trace_puts/__trace_bputs · f0160a5a
      zhangwei(Jovi) authored 
      The TRACE_ITER_PRINTK check in __trace_puts/__trace_bputs is missing,
so add it, to be consistent with __trace_printk/__trace_bprintk.
Those functions are all called by the same function: trace_printk().

Link: http://lkml.kernel.org/p/51E7A7D6.8090900@huawei.com

Cc: stable@vger.kernel.org # 3.11+
Signed-off-by: default avatarzhangwei(Jovi) <jovi.zhangwei@huawei.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      f0160a5a
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