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authorTrond Myklebust <trond.myklebust@primarydata.com>2015-02-26 17:42:42 -0500
committerTrond Myklebust <trond.myklebust@primarydata.com>2015-03-01 23:23:05 -0500
commit140e049c64ce848392adbf4678983ecc76888dde (patch)
tree1a278473e70aec757b36a2a2b4d7382e52f7b5b8
parentaa5accea404b2b92d39c1924cfeb90f6082f6389 (diff)
downloadlinux-140e049c64ce848392adbf4678983ecc76888dde.tar.bz2
NFS: Add a helper to set attribute barriers
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Tested-by: Chuck Lever <chuck.lever@oracle.com>
-rw-r--r--fs/nfs/inode.c16
-rw-r--r--include/linux/nfs_fs.h1
2 files changed, 17 insertions, 0 deletions
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 83107be3dd01..b0cbc1ba82da 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1260,6 +1260,22 @@ void nfs_fattr_init(struct nfs_fattr *fattr)
}
EXPORT_SYMBOL_GPL(nfs_fattr_init);
+/**
+ * nfs_fattr_set_barrier
+ * @fattr: attributes
+ *
+ * Used to set a barrier after an attribute was updated. This
+ * barrier ensures that older attributes from RPC calls that may
+ * have raced with our update cannot clobber these new values.
+ * Note that you are still responsible for ensuring that other
+ * operations which change the attribute on the server do not
+ * collide.
+ */
+void nfs_fattr_set_barrier(struct nfs_fattr *fattr)
+{
+ fattr->gencount = nfs_inc_attr_generation_counter();
+}
+
struct nfs_fattr *nfs_alloc_fattr(void)
{
struct nfs_fattr *fattr;
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 2f77e0c651c8..3a4ffb5856cd 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -369,6 +369,7 @@ extern struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ct
extern void nfs_put_lock_context(struct nfs_lock_context *l_ctx);
extern u64 nfs_compat_user_ino64(u64 fileid);
extern void nfs_fattr_init(struct nfs_fattr *fattr);
+extern void nfs_fattr_set_barrier(struct nfs_fattr *fattr);
extern unsigned long nfs_inc_attr_generation_counter(void);
extern struct nfs_fattr *nfs_alloc_fattr(void);