From 33344e0f7eaa2efbf9fcc55557d02e8603aa7012 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 7 Apr 2019 13:59:08 -0400 Subject: pNFS: Add tracking to limit the number of pNFS retries When the client is reading or writing using pNFS, and hits an error on the DS, then it typically sends a LAYOUTERROR and/or LAYOUTRETURN to the MDS, before redirtying the failed pages, and going for a new round of reads/writebacks. The problem is that if the server has no way to fix the DS, then we may need a way to interrupt this loop after a set number of attempts have been made. This patch adds an optional module parameter that allows the admin to specify how many times to retry the read/writeback process before failing with a fatal error. The default behaviour is to retry forever. Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker --- fs/nfs/pagelist.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'fs/nfs/pagelist.c') diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index b8301c40dd78..4a31284f411e 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -16,8 +16,8 @@ #include #include #include -#include #include +#include #include #include @@ -327,6 +327,7 @@ __nfs_create_request(struct nfs_lock_context *l_ctx, struct page *page, req->wb_bytes = count; req->wb_context = get_nfs_open_context(ctx); kref_init(&req->wb_kref); + req->wb_nio = 0; return req; } @@ -370,6 +371,7 @@ nfs_create_subreq(struct nfs_page *req, struct nfs_page *last, nfs_lock_request(ret); ret->wb_index = req->wb_index; nfs_page_group_init(ret, last); + ret->wb_nio = req->wb_nio; } return ret; } @@ -724,6 +726,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc, desc->pg_mirrors_dynamic = NULL; desc->pg_mirrors = desc->pg_mirrors_static; nfs_pageio_mirror_init(&desc->pg_mirrors[0], bsize); + desc->pg_maxretrans = 0; } /** @@ -983,6 +986,15 @@ static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc, return 0; mirror->pg_base = req->wb_pgbase; } + + if (desc->pg_maxretrans && req->wb_nio > desc->pg_maxretrans) { + if (NFS_SERVER(desc->pg_inode)->flags & NFS_MOUNT_SOFTERR) + desc->pg_error = -ETIMEDOUT; + else + desc->pg_error = -EIO; + return 0; + } + if (!nfs_can_coalesce_requests(prev, req, desc)) return 0; nfs_list_move_request(req, &mirror->pg_list); -- cgit v1.2.3