Fix zrele race in zrele_async that can cause hang

There is a race condition in zfs_zrele_async when we are checking if 
we would be the one to evict an inode. This can lead to a txg sync 
deadlock.

Instead of calling into iput directly, we attempt to perform the atomic 
decrement ourselves, unless that would set the i_count value to zero. 
In that case, we dispatch a call to iput to run later, to prevent a 
deadlock from occurring.

Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Matthew Ahrens <[email protected]>
Signed-off-by: Paul Dagnelie <[email protected]>
Closes #11527 
Closes #11530 

0 files changed, 0 insertions, 0 deletions