diff options
author | Jeff Layton <jeff.layton@primarydata.com> | 2014-07-22 13:52:06 -0400 |
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committer | J. Bruce Fields <bfields@redhat.com> | 2014-07-22 15:34:47 -0400 |
commit | d55a166c961714e18907f4723252f72097cd2d23 (patch) | |
tree | c8cd6088f54b2e85615107e3bfb59d25b8e6c3bf /net/sunrpc | |
parent | 72c0b0fb9f8a24612b6c33c8adf9e9406818981b (diff) |
nfsd: bump dl_time when unhashing delegation
There's a potential race between a lease break and DELEGRETURN call.
Suppose a lease break comes in and queues the workqueue job for a
delegation, but it doesn't run just yet. Then, a DELEGRETURN comes in
finds the delegation and calls destroy_delegation on it to unhash it and
put its primary reference.
Next, the workqueue job runs and queues the delegation back onto the
del_recall_lru list, issues the CB_RECALL and puts the final reference.
With that, the final reference to the delegation is put, but it's still
on the LRU list.
When we go to unhash a delegation, it's because we intend to get rid of
it soon afterward, so we don't want lease breaks to mess with it once
that occurs. Fix this by bumping the dl_time whenever we unhash a
delegation, to ensure that lease breaks don't monkey with it.
I believe this is a regression due to commit 02e1215f9f7 (nfsd: Avoid
taking state_lock while holding inode lock in nfsd_break_one_deleg).
Prior to that, the state_lock was held in the lm_break callback itself,
and that would have prevented this race.
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'net/sunrpc')
0 files changed, 0 insertions, 0 deletions