diff options
| author | Trond Myklebust <trond.myklebust@hammerspace.com> | 2021-06-01 11:10:05 -0400 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@hammerspace.com> | 2021-06-03 10:14:42 -0400 |
| commit | dfe1fe75e00e4c724ede7b9e593f6f680e446c5f (patch) | |
| tree | 2a74d5f01498891b11d85c89085737df12838413 /fs/nfs/nfs4_fs.h | |
| parent | d1b5c230e9cb6dddeab23f0f0c808e2b1c28d1b6 (diff) | |
NFSv4: Fix deadlock between nfs4_evict_inode() and nfs4_opendata_get_inode()
If the inode is being evicted, but has to return a delegation first,
then it can cause a deadlock in the corner case where the server reboots
before the delegreturn completes, but while the call to iget5_locked() in
nfs4_opendata_get_inode() is waiting for the inode free to complete.
Since the open call still holds a session slot, the reboot recovery
cannot proceed.
In order to break the logjam, we can turn the delegation return into a
privileged operation for the case where we're evicting the inode. We
know that in that case, there can be no other state recovery operation
that conflicts.
Reported-by: zhangxiaoxu (A) <zhangxiaoxu5@huawei.com>
Fixes: 5fcdfacc01f3 ("NFSv4: Return delegations synchronously in evict_inode")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Diffstat (limited to 'fs/nfs/nfs4_fs.h')
| -rw-r--r-- | fs/nfs/nfs4_fs.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index 065cb04222a1..543d916f79ab 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -205,6 +205,7 @@ struct nfs4_exception { struct inode *inode; nfs4_stateid *stateid; long timeout; + unsigned char task_is_privileged : 1; unsigned char delay : 1, recovering : 1, retry : 1; |