From: Peter Zijlstra 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 Cc: Trond Myklebust Signed-off-by: Andrew Morton --- fs/nfs/write.c | 4 ++-- include/linux/nfs_fs_sb.h | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff -puN fs/nfs/write.c~nfs-fix-congestion-control-use-atomic_longs fs/nfs/write.c --- a/fs/nfs/write.c~nfs-fix-congestion-control-use-atomic_longs +++ a/fs/nfs/write.c @@ -224,7 +224,7 @@ static int nfs_set_page_writeback(struct 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 @@ static void nfs_end_page_writeback(struc 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 -puN include/linux/nfs_fs_sb.h~nfs-fix-congestion-control-use-atomic_longs include/linux/nfs_fs_sb.h --- a/include/linux/nfs_fs_sb.h~nfs-fix-congestion-control-use-atomic_longs +++ a/include/linux/nfs_fs_sb.h @@ -82,7 +82,7 @@ struct nfs_server { 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 */ _