1. 01 Jul, 2013 1 commit
  2. 29 Jun, 2013 1 commit
    • Jeff Layton's avatar
      locks: protect most of the file_lock handling with i_lock · 1c8c601a
      Jeff Layton authored
      Having a global lock that protects all of this code is a clear
      scalability problem. Instead of doing that, move most of the code to be
      protected by the i_lock instead. The exceptions are the global lists
      that the ->fl_link sits on, and the ->fl_block list.
      
      ->fl_link is what connects these structures to the
      global lists, so we must ensure that we hold those locks when iterating
      over or updating these lists.
      
      Furthermore, sound deadlock detection requires that we hold the
      blocked_list state steady while checking for loops. We also must ensure
      that the search and update to the list are atomic.
      
      For the checking and insertion side of the blocked_list, push the
      acquisition of the global lock into __posix_lock_file and ensure that
      checking and update of the  blocked_list is done without dropping the
      lock in between.
      
      On the removal side, when waking up blocked lock waiters, take the
      global lock before walking the blocked list and dequeue the waiters from
      the global list prior to removal from the fl_block list.
      
      With this, deadlock detection should be race free while we minimize
      excessive file_lock_lock thrashing.
      
      Finally, in order to avoid a lock inversion problem when handling
      /proc/locks output we must ensure that manipulations of the fl_block
      list are also protected by the file_lock_lock.
      Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      1c8c601a
  3. 17 May, 2013 2 commits
    • Jim Schutt's avatar
      ceph: ceph_pagelist_append might sleep while atomic · 39be95e9
      Jim Schutt authored
      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: default avatarJim Schutt <jaschut@sandia.gov>
      Reviewed-by: default avatarAlex Elder <elder@inktank.com>
      39be95e9
    • Jim Schutt's avatar
      ceph: add cpu_to_le32() calls when encoding a reconnect capability · c420276a
      Jim Schutt authored
      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: default avatarJim Schutt <jaschut@sandia.gov>
      Reviewed-by: default avatarAlex Elder <elder@inktank.com>
      c420276a
  4. 23 Feb, 2013 1 commit
  5. 08 Jun, 2011 2 commits
  6. 01 Dec, 2010 2 commits
  7. 20 Oct, 2010 2 commits
    • Greg Farnum's avatar
      ceph: preallocate flock state without locks held · fca4451a
      Greg Farnum authored
      When the lock_kernel() turns into lock_flocks() and a spinlock, we won't
      be able to do allocations with the lock held.  Preallocate space without
      the lock, and retry if the lock state changes out from underneath us.
      Signed-off-by: default avatarGreg Farnum <gregf@hq.newdream.net>
      Signed-off-by: default avatarSage Weil <sage@newdream.net>
      fca4451a
    • Yehuda Sadeh's avatar
      ceph: factor out libceph from Ceph file system · 3d14c5d2
      Yehuda Sadeh authored
      This factors out protocol and low-level storage parts of ceph into a
      separate libceph module living in net/ceph and include/linux/ceph.  This
      is mostly a matter of moving files around.  However, a few key pieces
      of the interface change as well:
      
       - ceph_client becomes ceph_fs_client and ceph_client, where the latter
         captures the mon and osd clients, and the fs_client gets the mds client
         and file system specific pieces.
       - Mount option parsing and debugfs setup is correspondingly broken into
         two pieces.
       - The mon client gets a generic handler callback for otherwise unknown
         messages (mds map, in this case).
       - The basic supported/required feature bits can be expanded (and are by
         ceph_fs_client).
      
      No functional change, aside from some subtle error handling cases that got
      cleaned up in the refactoring process.
      Signed-off-by: default avatarSage Weil <sage@newdream.net>
      3d14c5d2
  8. 25 Aug, 2010 1 commit
    • Alan Cox's avatar
      ceph: Fix warnings · ad8453ab
      Alan Cox authored
      Just scrubbing some warnings so I can see real problem ones in the build
      noise. For 32bit we need to coax gcc politely into believing we really
      honestly intend to the casts. Using (u64)(unsigned long) means we cast from
      a pointer to a type of the right size and then extend it. This stops the
      warning spew.
      Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
      Signed-off-by: default avatarSage Weil <sage@newdream.net>
      ad8453ab
  9. 02 Aug, 2010 1 commit