From: Trond Myklebust trond.myklebust@hammerspace.com
stable inclusion from linux-4.19.191 commit e6681459e47a09fe61eac157aff93f2326d64025
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[ Upstream commit 9fdbfad1777cb4638f489eeb62d85432010c0031 ]
We need to use unsigned long subtraction and then convert to signed in order to deal correcly with C overflow rules.
Fixes: f5062003465c ("NFS: Set an attribute barrier on all updates") Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- fs/nfs/inode.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 905041eb24fee..c9670d822e1ca 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -1609,10 +1609,10 @@ EXPORT_SYMBOL_GPL(_nfs_display_fhandle); */ static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr) { - const struct nfs_inode *nfsi = NFS_I(inode); + unsigned long attr_gencount = NFS_I(inode)->attr_gencount;
- return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 || - ((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0); + return (long)(fattr->gencount - attr_gencount) > 0 || + (long)(attr_gencount - nfs_read_attr_generation_counter()) > 0; }
static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr) @@ -2042,7 +2042,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr) nfsi->attrtimeo_timestamp = now; } /* Set the barrier to be more recent than this fattr */ - if ((long)fattr->gencount - (long)nfsi->attr_gencount > 0) + if ((long)(fattr->gencount - nfsi->attr_gencount) > 0) nfsi->attr_gencount = fattr->gencount; }