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  1. 01 6月, 2018 2 次提交
    • N
      NFS: use cond_resched() when restarting walk of delegation list. · 3ca951b6
      由 NeilBrown 提交于 
      In three places we walk the list of delegations for an nfs_client
until an interesting one is found, then we act of that delegation
and restart the walk.

New delegations are added to the end of a list and the interesting
delegations are usually old, so in many case we won't repeat
a long walk over and over again, but it is possible - particularly if
the first server in the list has a large number of uninteresting
delegations.

In each cache the work done on interesting delegations will often
complete without sleeping, so this could loop many times without
giving up the CPU.

So add a cond_resched() at an appropriate point to avoid hogging the
CPU for too long.
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
      3ca951b6
    • N
      NFS: slight optimization for walking list for delegations · f3893491
      由 NeilBrown 提交于 
      There are 3 places where we walk the list of delegations
for an nfs_client.
In each case there are two nested loops, one for nfs_servers
and one for nfs_delegations.

When we find an interesting delegation we try to get an active
reference to the server.  If that fails, it is pointless to
continue to look at the other delegation for the server as
we will never be able to get an active reference.
So instead of continuing in the inner loop, break out
and continue in the outer loop.
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
      f3893491
  3. 11 4月, 2018 2 次提交
  5. 29 1月, 2018 1 次提交
  7. 18 11月, 2017 1 次提交
  9. 15 8月, 2017 1 次提交
  11. 02 12月, 2016 1 次提交
  13. 28 9月, 2016 9 次提交
  15. 18 5月, 2016 1 次提交
  17. 08 10月, 2015 1 次提交
  19. 21 9月, 2015 1 次提交
    • T
      NFSv4: Recovery of recalled read delegations is broken · 24311f88
      由 Trond Myklebust 提交于 
      When a read delegation is being recalled, and we're reclaiming the
cached opens, we need to make sure that we only reclaim read-only
modes.
A previous attempt to do this, relied on retrieving the delegation
type from the nfs4_opendata structure. Unfortunately, as Kinglong
pointed out, this field can only be set when performing reboot recovery.

Furthermore, if we call nfs4_open_recover(), then we end up clobbering
the state->flags for all modes that we're not recovering...

The fix is to have the delegation recall code pass this information
to the recovery call, and then refactor the recovery code so that
nfs4_open_delegation_recall() does not need to call nfs4_open_recover().
Reported-by: NKinglong Mee <kinglongmee@gmail.com>
Fixes: 39f897fd ("NFSv4: When returning a delegation, don't...")
Tested-by: NKinglong Mee <kinglongmee@gmail.com>
Cc: NeilBrown <neilb@suse.com>
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
      24311f88
  21. 08 9月, 2015 2 次提交
  23. 28 3月, 2015 1 次提交
  25. 13 3月, 2015 1 次提交
  27. 03 3月, 2015 4 次提交
  29. 02 3月, 2015 1 次提交
  31. 14 2月, 2015 1 次提交
  33. 25 1月, 2015 1 次提交
  35. 17 1月, 2015 3 次提交
  37. 13 11月, 2014 2 次提交
  39. 13 7月, 2014 1 次提交
  41. 03 3月, 2014 1 次提交
  43. 22 8月, 2013 1 次提交
  45. 29 6月, 2013 1 次提交
    • J
      locks: protect most of the file_lock handling with i_lock · 1c8c601a
      由 Jeff Layton 提交于 
      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: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      1c8c601a