From 140e049c64ce848392adbf4678983ecc76888dde Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 26 Feb 2015 17:42:42 -0500 Subject: [PATCH] NFS: Add a helper to set attribute barriers Signed-off-by: Trond Myklebust Tested-by: Chuck Lever --- fs/nfs/inode.c | 16 ++++++++++++++++ include/linux/nfs_fs.h | 1 + 2 files changed, 17 insertions(+) diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 83107be..b0cbc1b 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 2f77e0c..3a4ffb5 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); -- 2.7.4