[PATCH] NFS: cleanup: shrink struct nfs_open_context

 Remove the wait queue, and replace the functions that depended on it
 with wait_on_bit().

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

3 files changed, 28 insertions, 9 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index c80a81ff59c6..a38d4b22d1f8 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -848,7 +848,6 @@ struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, struct rp
                 ctx->state = NULL;
                 ctx->lockowner = current->files;
                 ctx->error = 0;
-                init_waitqueue_head(&ctx->waitq);
         }
         return ctx;
 }
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 4f1ba723848d..80777f99a58a 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -107,7 +107,7 @@ void nfs_unlock_request(struct nfs_page *req)
         smp_mb__before_clear_bit();
         clear_bit(PG_BUSY, &req->wb_flags);
         smp_mb__after_clear_bit();
-        wake_up_all(&req->wb_context->waitq);
+        wake_up_bit(&req->wb_flags, PG_BUSY);
         nfs_release_request(req);
 }
 
@@ -180,6 +180,17 @@ nfs_list_add_request(struct nfs_page *req, struct list_head *head)
         req->wb_list_head = head;
 }
 
+static int nfs_wait_bit_interruptible(void *word)
+{
+        int ret = 0;
+
+        if (signal_pending(current))
+                ret = -ERESTARTSYS;
+        else
+                schedule();
+        return ret;
+}
+
 /**
  * nfs_wait_on_request - Wait for a request to complete.
  * @req: request to wait upon.
@@ -190,12 +201,22 @@ nfs_list_add_request(struct nfs_page *req, struct list_head *head)
 int
 nfs_wait_on_request(struct nfs_page *req)
 {
-        struct inode    *inode = req->wb_context->dentry->d_inode;
-        struct rpc_clnt *clnt = NFS_CLIENT(inode);
-
-        if (!NFS_WBACK_BUSY(req))
-                return 0;
-        return nfs_wait_event(clnt, req->wb_context->waitq, !NFS_WBACK_BUSY(req));
+        struct rpc_clnt *clnt = NFS_CLIENT(req->wb_context->dentry->d_inode);
+        sigset_t oldmask;
+        int ret = 0;
+
+        if (!test_bit(PG_BUSY, &req->wb_flags))
+                goto out;
+        /*
+         * Note: the call to rpc_clnt_sigmask() suffices to ensure that we
+         *       are not interrupted if intr flag is not set
+         */
+        rpc_clnt_sigmask(clnt, &oldmask);
+        ret = out_of_line_wait_on_bit(&req->wb_flags, PG_BUSY,
+                        nfs_wait_bit_interruptible, TASK_INTERRUPTIBLE);
+        rpc_clnt_sigunmask(clnt, &oldmask);
+out:
+        return ret;
 }
 
 /**
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 68d5aae89972..0b01b96337f8 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -84,7 +84,6 @@ struct nfs_open_context {
         int error;
 
         struct list_head list;
-        wait_queue_head_t waitq;
 };
 
 /*