[PATCH 15/19] nfsd: set PF_FSTRANS when client_mutex is held.

NeilBrown
2014-04-16T04:19:39Z

When loop-back NFS with NFSv4 is in use, client_mutex might be needed
to reclaim memory, so any memory allocation while client_mutex is held
must avoid __GFP_FS, so best to set PF_FSTRANS.

Signed-off-by: NeilBrown <neilb@suse.de>
---
fs/nfsd/nfs4state.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index d5d070fbeb35..7b7fbcbe20cb 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -75,6 +75,7 @@ static int check_for_locks(struct nfs4_file *filp, struct nfs4_lockowner *lowner

/* Currently used for almost all code touching nfsv4 state: */
static DEFINE_MUTEX(client_mutex);
+static unsigned int client_mutex_pflags;

/*
* Currently used for the del_recall_lru and file hash table. In an
@@ -93,6 +94,7 @@ void
nfs4_lock_state(void)
{
mutex_lock(&client_mutex);
+ current_set_flags_nested(&client_mutex_pflags, PF_FSTRANS);
}

static void free_session(struct nfsd4_session *);
@@ -127,6 +129,7 @@ static __be32 nfsd4_get_session_locked(struct nfsd4_session *ses)
void
nfs4_unlock_state(void)
{
+ current_restore_flags_nested(&client_mutex_pflags, PF_FSTRANS);
mutex_unlock(&client_mutex);
}