diff options
| author | Trond Myklebust <trond.myklebust@hammerspace.com> | 2021-06-01 11:10:05 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-06-16 11:59:44 +0200 |
| commit | 34769f17e47cd09ec309a6e6638f84f65df253c9 (patch) | |
| tree | c8b02bb3ad8ebcf3782d0b2e6986d69173974323 /fs/nfs/nfs4_fs.h | |
| parent | 0057ecef9f324007c0ba5fcca4ddd131178ce78b (diff) | |
NFSv4: Fix deadlock between nfs4_evict_inode() and nfs4_opendata_get_inode()
[ Upstream commit dfe1fe75e00e4c724ede7b9e593f6f680e446c5f ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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 c4a98cbda6dd..5708b5a636f1 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -203,6 +203,7 @@ 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; |