goto out;
}
- spin_lock(&inode->i_lock);
- status = nfs_update_inode(inode, &fattr);
+ status = nfs_refresh_inode(inode, &fattr);
if (status) {
- spin_unlock(&inode->i_lock);
dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) refresh failed, error=%d\n",
inode->i_sb->s_id,
(long long)NFS_FILEID(inode), status);
goto out;
}
- spin_unlock(&inode->i_lock);
if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
nfs_zap_acl_cache(inode);
return 0;
}
+static int nfs_ctime_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
+{
+ return timespec_compare(&fattr->ctime, &inode->i_ctime) > 0;
+}
+
+static int nfs_size_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
+{
+ return nfs_size_to_loff_t(fattr->size) > i_size_read(inode);
+}
+
+/**
+ * nfs_inode_attrs_need_update - check if the inode attributes need updating
+ * @inode - pointer to inode
+ * @fattr - attributes
+ *
+ * Attempt to divine whether or not an RPC call reply carrying stale
+ * attributes got scheduled after another call carrying updated ones.
+ *
+ * To do so, the function first assumes that a more recent ctime means
+ * that the attributes in fattr are newer, however it also attempt to
+ * catch the case where ctime either didn't change, or went backwards
+ * (if someone reset the clock on the server) by looking at whether
+ * or not this RPC call was started after the inode was last updated.
+ * Note also the check for jiffy wraparound if the last_updated timestamp
+ * is later than 'jiffies'.
+ *
+ * The function returns 'true' if it thinks the attributes in 'fattr' are
+ * more recent than the ones cached in the inode.
+ *
+ */
+static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
+{
+ const struct nfs_inode *nfsi = NFS_I(inode);
+
+ return nfs_ctime_need_update(inode, fattr) ||
+ nfs_size_need_update(inode, fattr) ||
+ time_after(fattr->time_start, nfsi->last_updated) ||
+ time_after(nfsi->last_updated, jiffies);
+}
+
+static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
+{
+ if (nfs_inode_attrs_need_update(inode, fattr))
+ return nfs_update_inode(inode, fattr);
+ return nfs_check_inode_attributes(inode, fattr);
+}
+
/**
* nfs_refresh_inode - try to update the inode attribute cache
* @inode - pointer to inode
*/
int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
{
- struct nfs_inode *nfsi = NFS_I(inode);
int status;
if ((fattr->valid & NFS_ATTR_FATTR) == 0)
return 0;
spin_lock(&inode->i_lock);
- if (time_after(fattr->time_start, nfsi->last_updated))
- status = nfs_update_inode(inode, fattr);
- else
- status = nfs_check_inode_attributes(inode, fattr);
-
+ status = nfs_refresh_inode_locked(inode, fattr);
spin_unlock(&inode->i_lock);
return status;
}
+static int nfs_post_op_update_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
+{
+ struct nfs_inode *nfsi = NFS_I(inode);
+
+ nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
+ if (S_ISDIR(inode->i_mode))
+ nfsi->cache_validity |= NFS_INO_INVALID_DATA;
+ if ((fattr->valid & NFS_ATTR_FATTR) == 0)
+ return 0;
+ return nfs_refresh_inode_locked(inode, fattr);
+}
+
/**
* nfs_post_op_update_inode - try to update the inode attribute cache
* @inode - pointer to inode
*/
int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
{
- struct nfs_inode *nfsi = NFS_I(inode);
+ int status;
spin_lock(&inode->i_lock);
- nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
- if (S_ISDIR(inode->i_mode))
- nfsi->cache_validity |= NFS_INO_INVALID_DATA;
+ status = nfs_post_op_update_inode_locked(inode, fattr);
spin_unlock(&inode->i_lock);
- return nfs_refresh_inode(inode, fattr);
+ return status;
}
/**
*/
int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
{
+ int status;
+
+ spin_lock(&inode->i_lock);
+ /* Don't do a WCC update if these attributes are already stale */
+ if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
+ !nfs_inode_attrs_need_update(inode, fattr)) {
+ fattr->valid &= ~(NFS_ATTR_WCC_V4|NFS_ATTR_WCC);
+ goto out_noforce;
+ }
if ((fattr->valid & NFS_ATTR_FATTR_V4) != 0 &&
(fattr->valid & NFS_ATTR_WCC_V4) == 0) {
fattr->pre_change_attr = NFS_I(inode)->change_attr;
fattr->pre_size = i_size_read(inode);
fattr->valid |= NFS_ATTR_WCC;
}
- return nfs_post_op_update_inode(inode, fattr);
+out_noforce:
+ status = nfs_post_op_update_inode_locked(inode, fattr);
+ spin_unlock(&inode->i_lock);
+ return status;
}
/*
#endif
}
-static void init_once(struct kmem_cache * cachep, void *foo)
+static void init_once(void *foo)
{
struct nfs_inode *nfsi = (struct nfs_inode *) foo;