From: NeilBrown <neilb@suse.com>
Date: Wed, 13 Dec 2017 09:41:04 +1100
Subject: [PATCH] NFSv4: always set NFS_LOCK_LOST when a lock is lost.
Patch-mainline: v4.16-rc1
Git-commit: dce2630c7da73b0634686bca557cc8945cc450c8
References: bsc#1068951
There are 2 comments in the NFSv4 code which suggest that
SIGLOST should possibly be sent to a process. In these
cases a lock has been lost.
The current practice is to set NFS_LOCK_LOST so that
read/write returns EIO when a lock is lost.
So change these comments to code when sets NFS_LOCK_LOST.
One case is when lock recovery after apparent server restart fails
with NFS4ERR_DENIED, NFS4ERR_RECLAIM_BAD, NFS4ERRO_RECLAIM_CONFLICT.
The other case is when lease recovery fails with NFS4ERR_DENIED.
In an ideal world, these should not happen. However I have a packet
trace showing an NFSv4.1 session getting NFS4ERR_BADSESSION after
an extended network parition. The NFSv4.1 client treats this like
server reboot until/unless it get NFS4ERR_NO_GRACE, in which case
it switches over to "nograce" recovery mode.
In this network trace, the client attempts to recover a lock
and the server (incorrectly) reports NFS4ERR_DENIED rather
than NFS4ERR_NO_GRACE. This leads to the ineffective comment
and the client then continues to write using the OPEN stateid.
Note that I have not tested this as I do not have direct access to a
faulty NFS server. Once I get confirmation I will provide an update.
Signed-off-by: NeilBrown <neilb@suse.com>
Acked-by: NeilBrown <neilb@suse.com>
---
fs/nfs/nfs4proc.c | 12 ++++++++----
fs/nfs/nfs4state.c | 5 ++++-
2 files changed, 12 insertions(+), 5 deletions(-)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1784,7 +1784,7 @@ static int nfs4_open_reclaim(struct nfs4
return ret;
}
-static int nfs4_handle_delegation_recall_error(struct nfs_server *server, struct nfs4_state *state, const nfs4_stateid *stateid, int err)
+static int nfs4_handle_delegation_recall_error(struct nfs_server *server, struct nfs4_state *state, const nfs4_stateid *stateid, struct file_lock *fl, int err)
{
switch (err) {
default:
@@ -1831,7 +1831,11 @@ static int nfs4_handle_delegation_recall
return -EAGAIN;
case -ENOMEM:
case -NFS4ERR_DENIED:
- /* kill_proc(fl->fl_pid, SIGLOST, 1); */
+ if (fl) {
+ struct nfs4_lock_state *lsp = fl->fl_u.nfs4_fl.owner;
+ if (lsp)
+ set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
+ }
return 0;
}
return err;
@@ -1867,7 +1871,7 @@ int nfs4_open_delegation_recall(struct n
err = nfs4_open_recover_helper(opendata, FMODE_READ);
}
nfs4_opendata_put(opendata);
- return nfs4_handle_delegation_recall_error(server, state, stateid, err);
+ return nfs4_handle_delegation_recall_error(server, state, stateid, NULL, err);
}
static void nfs4_open_confirm_prepare(struct rpc_task *task, void *calldata)
@@ -6159,7 +6163,7 @@ int nfs4_lock_delegation_recall(struct f
if (err != 0)
return err;
err = _nfs4_do_setlk(state, F_SETLK, fl, NFS_LOCK_NEW);
- return nfs4_handle_delegation_recall_error(server, state, stateid, err);
+ return nfs4_handle_delegation_recall_error(server, state, stateid, fl, err);
}
struct nfs_release_lockowner_data {
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1398,6 +1398,7 @@ static int nfs4_reclaim_locks(struct nfs
struct inode *inode = state->inode;
struct nfs_inode *nfsi = NFS_I(inode);
struct file_lock *fl;
+ struct nfs4_lock_state *lsp;
int status = 0;
struct file_lock_context *flctx = inode->i_flctx;
struct list_head *list;
@@ -1438,7 +1439,9 @@ restart:
case -NFS4ERR_DENIED:
case -NFS4ERR_RECLAIM_BAD:
case -NFS4ERR_RECLAIM_CONFLICT:
- /* kill_proc(fl->fl_pid, SIGLOST, 1); */
+ lsp = fl->fl_u.nfs4_fl.owner;
+ if (lsp)
+ set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
status = 0;
}
spin_lock(&flctx->flc_lock);