The replay cursor should be updated properly when close happened
during replay, otherwise, ptlrpc_replay_next() could run into a
dead loop due to an invalid replay cursor:
- replay cursor is moved to an open request during replay;
- application close that open file, so the rq_replay of the open
request is cleared;
- ptlrpc_replay_next() calls ptlrpc_free_committed() to free
committed/closed requests, the open request is removed from
the committed list, so the replay cursor is changed to an
empty list_head now. The open request won't be freed now since
it's still held by the pending close request;
- ptlrpc_replay_next() continue to move the replay cursor to
next and run into a dead loop at the end;
Another change in this patch is to remove the out of date comments
in ptlrpc_replay_next() and cover the whole process of finding
replay request within imp_lock, because:
1. With two separated replay lists and replay cursor introduced,
finding replay request won't take much time as before, it's
not necessary to do this "lock -> unlock -> lock -> unlock"
trick anymore;
2. Nowadays there are various kind of non-replay requests are
allowed during recovery, so ptlrpc_free_committed() may run in
parallel to remove an open request while ptlrpc_replay_next()
is iterating the open requests list;
Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-8765
Reviewed-on: https://review.whamcloud.com/23418
Reviewed-by: Yang Sheng <yang.sheng@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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