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NFS: avoid spurious warning of lost lock that is being unlocked.

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When the NFSv4 state manager recovers state after a server restart, it
reports that locks have been lost if it finds any lock state for which
recovery hasn't been successful.  i.e. any for which
NFS_LOCK_INITIALIZED is not set.

However it only tries to recover locks that are still linked to
inode->i_flctx.  So if a lock has been removed from inode->i_flctx, but
the state for that lock has not yet been destroyed, then a spurious
warning results.

nfs4_proc_unlck() calls locks_lock_inode_wait() - which removes the lock
from ->i_flctx - before sending the unlock request to the server and
before the final nfs4_put_lock_state() is called.  This allows a window
in which a spurious warning can be produced.

So add a new flag NFS_LOCK_UNLOCKING which is set once the decision has
been made to unlock the lock.  This will prevent it from triggering any
warning.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
NeilBrown 2022-10-10 10:26:51 +11:00 committed by Trond Myklebust
parent 5559405df6
commit ef8d98f20d
3 changed files with 5 additions and 2 deletions
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1
fs/nfs/nfs4_fs.h
View File

@ -149,6 +149,7 @@ struct nfs4_lock_state {
struct nfs4_state * ls_state; /* Pointer to open state */
#define NFS_LOCK_INITIALIZED 0
#define NFS_LOCK_LOST 1
#define NFS_LOCK_UNLOCKING 2
unsigned long ls_flags;
struct nfs_seqid_counter ls_seqid;
nfs4_stateid ls_stateid;

3
fs/nfs/nfs4proc.c
View File

@ -7023,12 +7023,13 @@ static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock *
mutex_unlock(&sp->so_delegreturn_mutex);
goto out;
}
lsp = request->fl_u.nfs4_fl.owner;
set_bit(NFS_LOCK_UNLOCKING, &lsp->ls_flags);
up_read(&nfsi->rwsem);
mutex_unlock(&sp->so_delegreturn_mutex);
if (status != 0)
goto out;
/* Is this a delegated lock? */
lsp = request->fl_u.nfs4_fl.owner;
if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) == 0)
goto out;
alloc_seqid = NFS_SERVER(inode)->nfs_client->cl_mvops->alloc_seqid;

3
fs/nfs/nfs4state.c
View File

@ -1619,7 +1619,8 @@ static int __nfs4_reclaim_open_state(struct nfs4_state_owner *sp, struct nfs4_st
spin_lock(&state->state_lock);
list_for_each_entry(lock, &state->lock_states, ls_locks) {
trace_nfs4_state_lock_reclaim(state, lock);
if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags) &&
!test_bit(NFS_LOCK_UNLOCKING, &lock->ls_flags))
*lost_locks += 1;
}
spin_unlock(&state->state_lock);