NFSv4: Defer inode revalidation when setting up a delegation

Currently we force a synchronous call to __nfs_revalidate_inode() in
nfs_inode_set_delegation(). This not only ensures that we cannot call
nfs_inode_set_delegation from an asynchronous context, but it also slows
down any call to open().

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

3 files changed, 10 insertions, 5 deletions

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 56f4f6a99d4e..20ac403469a0 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -124,10 +124,6 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct
         struct nfs_delegation *delegation;
         int status = 0;
 
-        /* Ensure we first revalidate the attributes and page cache! */
-        if ((nfsi->cache_validity & (NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_ATTR)))
-                __nfs_revalidate_inode(NFS_SERVER(inode), inode);
-
         delegation = kmalloc(sizeof(*delegation), GFP_KERNEL);
         if (delegation == NULL)
                 return -ENOMEM;
@@ -154,6 +150,12 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct
                         status = -EIO;
                 }
         }
+
+        /* Ensure we revalidate the attributes and page cache! */
+        spin_lock(&inode->i_lock);
+        nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
+        spin_unlock(&inode->i_lock);
+
         spin_unlock(&clp->cl_lock);
         kfree(delegation);
         return status;
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 9d5124166d20..3d9fccf4ef93 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1072,8 +1072,10 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
                 invalid &= ~NFS_INO_INVALID_DATA;
         if (data_stable)
                 invalid &= ~(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ATIME|NFS_INO_REVAL_PAGECACHE);
-        if (!nfs_have_delegation(inode, FMODE_READ))
+        if (!nfs_have_delegation(inode, FMODE_READ) ||
+                        (nfsi->cache_validity & NFS_INO_REVAL_FORCED))
                 nfsi->cache_validity |= invalid;
+        nfsi->cache_validity &= ~NFS_INO_REVAL_FORCED;
 
         return 0;
  out_changed:
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index cf395351cdd4..e94971040de9 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -184,6 +184,7 @@ struct nfs_inode {
 #define NFS_INO_INVALID_ACCESS  0x0008          /* cached access cred invalid */
 #define NFS_INO_INVALID_ACL     0x0010          /* cached acls are invalid */
 #define NFS_INO_REVAL_PAGECACHE 0x0020          /* must revalidate pagecache */
+#define NFS_INO_REVAL_FORCED    0x0040          /* force revalidation ignoring a delegation */
 
 /*
  * Bit offsets in flags field