From 135444126a1175912b43366f6109cb297018f034 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 2 Nov 2015 10:11:17 -0500 Subject: [PATCH] pNFS/flexfiles: When mirrored, retry failed reads by switching mirrors If the pNFS/flexfiles file is mirrored, and a read to one mirror fails, then we should bump the mirror index, so that we retry to a different mirror. Once we've iterated through all mirrors and all failed, we can return the layout and issue a new LAYOUTGET. Signed-off-by: Trond Myklebust --- fs/nfs/flexfilelayout/flexfilelayout.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c index fbc5a56de875..7fc14b90886e 100644 --- a/fs/nfs/flexfilelayout/flexfilelayout.c +++ b/fs/nfs/flexfilelayout/flexfilelayout.c @@ -741,17 +741,17 @@ ff_layout_alloc_commit_info(struct pnfs_layout_segment *lseg, } static struct nfs4_pnfs_ds * -ff_layout_choose_best_ds_for_read(struct nfs_pageio_descriptor *pgio, +ff_layout_choose_best_ds_for_read(struct pnfs_layout_segment *lseg, + int start_idx, int *best_idx) { - struct nfs4_ff_layout_segment *fls; + struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg); struct nfs4_pnfs_ds *ds; int idx; - fls = FF_LAYOUT_LSEG(pgio->pg_lseg); /* mirrors are sorted by efficiency */ - for (idx = 0; idx < fls->mirror_array_cnt; idx++) { - ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, idx, false); + for (idx = start_idx; idx < fls->mirror_array_cnt; idx++) { + ds = nfs4_ff_layout_prepare_ds(lseg, idx, false); if (ds) { *best_idx = idx; return ds; @@ -782,7 +782,7 @@ ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio, if (pgio->pg_lseg == NULL) goto out_mds; - ds = ff_layout_choose_best_ds_for_read(pgio, &ds_idx); + ds = ff_layout_choose_best_ds_for_read(pgio->pg_lseg, 0, &ds_idx); if (!ds) goto out_mds; mirror = FF_LAYOUT_COMP(pgio->pg_lseg, ds_idx); @@ -1171,6 +1171,10 @@ static int ff_layout_read_done_cb(struct rpc_task *task, switch (err) { case -NFS4ERR_RESET_TO_PNFS: + if (ff_layout_choose_best_ds_for_read(hdr->lseg, + hdr->pgio_mirror_idx + 1, + &hdr->pgio_mirror_idx)) + goto out_eagain; set_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE, &hdr->lseg->pls_layout->plh_flags); pnfs_read_resend_pnfs(hdr); @@ -1179,11 +1183,13 @@ static int ff_layout_read_done_cb(struct rpc_task *task, ff_layout_reset_read(hdr); return task->tk_status; case -EAGAIN: - rpc_restart_call_prepare(task); - return -EAGAIN; + goto out_eagain; } return 0; +out_eagain: + rpc_restart_call_prepare(task); + return -EAGAIN; } static bool