nfs: fix congestion control: use atomic_longs
Change the atomic_t in struct nfs_server to atomic_long_t in anticipation
of machines that can handle 8+TB of (4K) pages under writeback.
However I suspect other things in NFS will start going *bang* by then.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 522cd41..de92b95 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -224,7 +224,7 @@
struct inode *inode = page->mapping->host;
struct nfs_server *nfss = NFS_SERVER(inode);
- if (atomic_inc_return(&nfss->writeback) >
+ if (atomic_long_inc_return(&nfss->writeback) >
NFS_CONGESTION_ON_THRESH)
set_bdi_congested(&nfss->backing_dev_info, WRITE);
}
@@ -237,7 +237,7 @@
struct nfs_server *nfss = NFS_SERVER(inode);
end_page_writeback(page);
- if (atomic_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) {
+ if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) {
clear_bdi_congested(&nfss->backing_dev_info, WRITE);
congestion_end(WRITE);
}
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index c95d5e6..52b4378 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -82,7 +82,7 @@
struct rpc_clnt * client_acl; /* ACL RPC client handle */
struct nfs_iostats * io_stats; /* I/O statistics */
struct backing_dev_info backing_dev_info;
- atomic_t writeback; /* number of writeback pages */
+ atomic_long_t writeback; /* number of writeback pages */
int flags; /* various flags */
unsigned int caps; /* server capabilities */
unsigned int rsize; /* read size */