NFSv4: Don't use GFP_KERNEL allocations in state recovery

We do not want to have the state recovery thread kick off and wait for a
memory reclaim, since that may deadlock when the writebacks end up
waiting for the state recovery thread to complete.

The safe thing is therefore to use GFP_NOFS in all open, close,
delegation return, lock, etc. operations that may be called by the
state recovery thread.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 11 insertions, 10 deletions

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index cd2d90400d46..34acf5926fdc 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -366,7 +366,7 @@ nfs4_alloc_state_owner(void)
 {
         struct nfs4_state_owner *sp;
 
-        sp = kzalloc(sizeof(*sp),GFP_KERNEL);
+        sp = kzalloc(sizeof(*sp),GFP_NOFS);
         if (!sp)
                 return NULL;
         spin_lock_init(&sp->so_lock);
@@ -440,7 +440,7 @@ nfs4_alloc_open_state(void)
 {
         struct nfs4_state *state;
 
-        state = kzalloc(sizeof(*state), GFP_KERNEL);
+        state = kzalloc(sizeof(*state), GFP_NOFS);
         if (!state)
                 return NULL;
         atomic_set(&state->count, 1);
@@ -542,7 +542,8 @@ void nfs4_put_open_state(struct nfs4_state *state)
 /*
  * Close the current file.
  */
-static void __nfs4_close(struct path *path, struct nfs4_state *state, fmode_t fmode, int wait)
+static void __nfs4_close(struct path *path, struct nfs4_state *state,
+                fmode_t fmode, gfp_t gfp_mask, int wait)
 {
         struct nfs4_state_owner *owner = state->owner;
         int call_close = 0;
@@ -583,17 +584,17 @@ static void __nfs4_close(struct path *path, struct nfs4_state *state, fmode_t fm
                 nfs4_put_open_state(state);
                 nfs4_put_state_owner(owner);
         } else
-                nfs4_do_close(path, state, wait);
+                nfs4_do_close(path, state, gfp_mask, wait);
 }
 
 void nfs4_close_state(struct path *path, struct nfs4_state *state, fmode_t fmode)
 {
-        __nfs4_close(path, state, fmode, 0);
+        __nfs4_close(path, state, fmode, GFP_NOFS, 0);
 }
 
 void nfs4_close_sync(struct path *path, struct nfs4_state *state, fmode_t fmode)
 {
-        __nfs4_close(path, state, fmode, 1);
+        __nfs4_close(path, state, fmode, GFP_KERNEL, 1);
 }
 
 /*
@@ -623,7 +624,7 @@ static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, f
         struct nfs4_lock_state *lsp;
         struct nfs_client *clp = state->owner->so_client;
 
-        lsp = kzalloc(sizeof(*lsp), GFP_KERNEL);
+        lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
         if (lsp == NULL)
                 return NULL;
         rpc_init_wait_queue(&lsp->ls_sequence.wait, "lock_seqid_waitqueue");
@@ -759,11 +760,11 @@ void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t f
         nfs4_put_lock_state(lsp);
 }
 
-struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter)
+struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
 {
         struct nfs_seqid *new;
 
-        new = kmalloc(sizeof(*new), GFP_KERNEL);
+        new = kmalloc(sizeof(*new), gfp_mask);
         if (new != NULL) {
                 new->sequence = counter;
                 INIT_LIST_HEAD(&new->list);
@@ -1352,7 +1353,7 @@ static int nfs4_recall_slot(struct nfs_client *clp)
 
         nfs4_begin_drain_session(clp);
         new = kmalloc(fc_tbl->target_max_slots * sizeof(struct nfs4_slot),
-                      GFP_KERNEL);
+                      GFP_NOFS);
         if (!new)
                 return -ENOMEM;