NFS: Convert nfs_attr_generation_counter into an atomic_long

The most important property we need from nfs_attr_generation_counter is
monotonicity, which is not guaranteed by the current system of smp memory
barriers. We should convert it to an atomic_long_t, and drop the memory
barriers.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2008-10-28 15:21:40 -04:00
parent 2a9e1cfa23
commit ae05f26940

View File

@ -908,21 +908,16 @@ static int nfs_size_need_update(const struct inode *inode, const struct nfs_fatt
return nfs_size_to_loff_t(fattr->size) > i_size_read(inode);
}
static unsigned long nfs_attr_generation_counter;
static atomic_long_t nfs_attr_generation_counter;
static unsigned long nfs_read_attr_generation_counter(void)
{
smp_rmb();
return nfs_attr_generation_counter;
return atomic_long_read(&nfs_attr_generation_counter);
}
unsigned long nfs_inc_attr_generation_counter(void)
{
unsigned long ret;
smp_rmb();
ret = ++nfs_attr_generation_counter;
smp_wmb();
return ret;
return atomic_long_inc_return(&nfs_attr_generation_counter);
}
void nfs_fattr_init(struct nfs_fattr *fattr)