NFS: Clean up weak cache consistency code

 ...and ensure that nfs_update_inode() respects wcc

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

1 files changed, 40 insertions, 20 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 2c7f8aac1dec..7270b1d73d30 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1248,6 +1248,33 @@ void nfs_end_data_update(struct inode *inode)
         atomic_dec(&nfsi->data_updates);
 }
 
+static void nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
+{
+        struct nfs_inode *nfsi = NFS_I(inode);
+
+        if ((fattr->valid & NFS_ATTR_PRE_CHANGE) != 0
+                        && nfsi->change_attr == fattr->pre_change_attr) {
+                nfsi->change_attr = fattr->change_attr;
+                nfsi->cache_change_attribute = jiffies;
+        }
+
+        /* If we have atomic WCC data, we may update some attributes */
+        if ((fattr->valid & NFS_ATTR_WCC) != 0) {
+                if (timespec_equal(&inode->i_ctime, &fattr->pre_ctime)) {
+                        memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
+                        nfsi->cache_change_attribute = jiffies;
+                }
+                if (timespec_equal(&inode->i_mtime, &fattr->pre_mtime)) {
+                        memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
+                        nfsi->cache_change_attribute = jiffies;
+                }
+                if (inode->i_size == fattr->pre_size && nfsi->npages == 0) {
+                        inode->i_size = fattr->size;
+                        nfsi->cache_change_attribute = jiffies;
+                }
+        }
+}
+
 /**
  * nfs_check_inode_attributes - verify consistency of the inode attribute cache
  * @inode - pointer to inode
@@ -1264,22 +1291,20 @@ static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fat
         int data_unstable;
 
 
+        if ((fattr->valid & NFS_ATTR_FATTR) == 0)
+                return 0;
+
         /* Are we in the process of updating data on the server? */
         data_unstable = nfs_caches_unstable(inode);
 
-        if (fattr->valid & NFS_ATTR_FATTR_V4) {
-                if ((fattr->valid & NFS_ATTR_PRE_CHANGE) != 0
-                                && nfsi->change_attr == fattr->pre_change_attr)
-                        nfsi->change_attr = fattr->change_attr;
-                if (nfsi->change_attr != fattr->change_attr) {
-                        nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
-                        if (!data_unstable)
-                                nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE;
-                }
-        }
+        /* Do atomic weak cache consistency updates */
+        nfs_wcc_update_inode(inode, fattr);
 
-        if ((fattr->valid & NFS_ATTR_FATTR) == 0) {
-                return 0;
+        if ((fattr->valid & NFS_ATTR_FATTR_V4) != 0 &&
+                        nfsi->change_attr != fattr->change_attr) {
+                nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
+                if (!data_unstable)
+                        nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE;
         }
 
         /* Has the inode gone and changed behind our back? */
@@ -1291,14 +1316,6 @@ static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fat
         cur_size = i_size_read(inode);
         new_isize = nfs_size_to_loff_t(fattr->size);
 
-        /* If we have atomic WCC data, we may update some attributes */
-        if ((fattr->valid & NFS_ATTR_WCC) != 0) {
-                if (timespec_equal(&inode->i_ctime, &fattr->pre_ctime))
-                        memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
-                if (timespec_equal(&inode->i_mtime, &fattr->pre_mtime))
-                        memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
-        }
-
         /* Verify a few of the more important attributes */
         if (!timespec_equal(&inode->i_mtime, &fattr->mtime)) {
                 nfsi->cache_validity |= NFS_INO_INVALID_ATTR;
@@ -1426,6 +1443,9 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
         if (data_stable)
                 nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ATIME);
 
+        /* Do atomic weak cache consistency updates */
+        nfs_wcc_update_inode(inode, fattr);
+
         /* Check if our cached file size is stale */
         new_isize = nfs_size_to_loff_t(fattr->size);
         cur_isize = i_size_read(inode);