From: Tigran Mkrtchyan Date: Fri, 27 Jun 2025 07:17:51 +0000 (+0200) Subject: pNFS/flexfiles: don't attempt pnfs on fatal DS errors X-Git-Tag: io_uring-6.17-20250815~23^2~18 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=f06bedfa62d57f7b67d44aacd6badad2e13a803f;p=linux-block.git pNFS/flexfiles: don't attempt pnfs on fatal DS errors When an applications get killed (SIGTERM/SIGINT) while pNFS client performs a connection to DS, client ends in an infinite loop of connect-disconnect. This source of the issue, it that flexfilelayoutdev#nfs4_ff_layout_prepare_ds gets an error on nfs4_pnfs_ds_connect with status ERESTARTSYS, which is set by rpc_signal_task, but the error is treated as transient, thus retried. The issue is reproducible with Ctrl+C the following script(there should be ~1000 files in a directory, client should must not have any connections to DSes): ``` echo 3 > /proc/sys/vm/drop_caches for i in * do head -1 $i done ``` The change aims to propagate the nfs4_ff_layout_prepare_ds error state to the caller that can decide whatever this is a retryable error or not. Signed-off-by: Tigran Mkrtchyan Link: https://lore.kernel.org/r/20250627071751.189663-1-tigran.mkrtchyan@desy.de Fixes: 260f32adb88d ("pNFS/flexfiles: Check the result of nfs4_pnfs_ds_connect") Signed-off-by: Trond Myklebust --- diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c index 4bea008dbebd..8dc921d83538 100644 --- a/fs/nfs/flexfilelayout/flexfilelayout.c +++ b/fs/nfs/flexfilelayout/flexfilelayout.c @@ -762,14 +762,14 @@ ff_layout_choose_ds_for_read(struct pnfs_layout_segment *lseg, { struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg); struct nfs4_ff_layout_mirror *mirror; - struct nfs4_pnfs_ds *ds; + struct nfs4_pnfs_ds *ds = ERR_PTR(-EAGAIN); u32 idx; /* mirrors are initially sorted by efficiency */ for (idx = start_idx; idx < fls->mirror_array_cnt; idx++) { mirror = FF_LAYOUT_COMP(lseg, idx); ds = nfs4_ff_layout_prepare_ds(lseg, mirror, false); - if (!ds) + if (IS_ERR(ds)) continue; if (check_device && @@ -777,10 +777,10 @@ ff_layout_choose_ds_for_read(struct pnfs_layout_segment *lseg, continue; *best_idx = idx; - return ds; + break; } - return NULL; + return ds; } static struct nfs4_pnfs_ds * @@ -942,7 +942,7 @@ retry: for (i = 0; i < pgio->pg_mirror_count; i++) { mirror = FF_LAYOUT_COMP(pgio->pg_lseg, i); ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, mirror, true); - if (!ds) { + if (IS_ERR(ds)) { if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg)) goto out_mds; pnfs_generic_pg_cleanup(pgio); @@ -1867,6 +1867,7 @@ ff_layout_read_pagelist(struct nfs_pgio_header *hdr) u32 idx = hdr->pgio_mirror_idx; int vers; struct nfs_fh *fh; + bool ds_fatal_error = false; dprintk("--> %s ino %lu pgbase %u req %zu@%llu\n", __func__, hdr->inode->i_ino, @@ -1874,8 +1875,10 @@ ff_layout_read_pagelist(struct nfs_pgio_header *hdr) mirror = FF_LAYOUT_COMP(lseg, idx); ds = nfs4_ff_layout_prepare_ds(lseg, mirror, false); - if (!ds) + if (IS_ERR(ds)) { + ds_fatal_error = nfs_error_is_fatal(PTR_ERR(ds)); goto out_failed; + } ds_clnt = nfs4_ff_find_or_create_ds_client(mirror, ds->ds_clp, hdr->inode); @@ -1923,7 +1926,7 @@ ff_layout_read_pagelist(struct nfs_pgio_header *hdr) return PNFS_ATTEMPTED; out_failed: - if (ff_layout_avoid_mds_available_ds(lseg)) + if (ff_layout_avoid_mds_available_ds(lseg) && !ds_fatal_error) return PNFS_TRY_AGAIN; trace_pnfs_mds_fallback_read_pagelist(hdr->inode, hdr->args.offset, hdr->args.count, @@ -1945,11 +1948,14 @@ ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync) int vers; struct nfs_fh *fh; u32 idx = hdr->pgio_mirror_idx; + bool ds_fatal_error = false; mirror = FF_LAYOUT_COMP(lseg, idx); ds = nfs4_ff_layout_prepare_ds(lseg, mirror, true); - if (!ds) + if (IS_ERR(ds)) { + ds_fatal_error = nfs_error_is_fatal(PTR_ERR(ds)); goto out_failed; + } ds_clnt = nfs4_ff_find_or_create_ds_client(mirror, ds->ds_clp, hdr->inode); @@ -2000,7 +2006,7 @@ ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync) return PNFS_ATTEMPTED; out_failed: - if (ff_layout_avoid_mds_available_ds(lseg)) + if (ff_layout_avoid_mds_available_ds(lseg) && !ds_fatal_error) return PNFS_TRY_AGAIN; trace_pnfs_mds_fallback_write_pagelist(hdr->inode, hdr->args.offset, hdr->args.count, @@ -2043,7 +2049,7 @@ static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how) idx = calc_ds_index_from_commit(lseg, data->ds_commit_index); mirror = FF_LAYOUT_COMP(lseg, idx); ds = nfs4_ff_layout_prepare_ds(lseg, mirror, true); - if (!ds) + if (IS_ERR(ds)) goto out_err; ds_clnt = nfs4_ff_find_or_create_ds_client(mirror, ds->ds_clp, diff --git a/fs/nfs/flexfilelayout/flexfilelayoutdev.c b/fs/nfs/flexfilelayout/flexfilelayoutdev.c index 656d5c50bbce..30365ec782bb 100644 --- a/fs/nfs/flexfilelayout/flexfilelayoutdev.c +++ b/fs/nfs/flexfilelayout/flexfilelayoutdev.c @@ -370,11 +370,11 @@ nfs4_ff_layout_prepare_ds(struct pnfs_layout_segment *lseg, struct nfs4_ff_layout_mirror *mirror, bool fail_return) { - struct nfs4_pnfs_ds *ds = NULL; + struct nfs4_pnfs_ds *ds; struct inode *ino = lseg->pls_layout->plh_inode; struct nfs_server *s = NFS_SERVER(ino); unsigned int max_payload; - int status; + int status = -EAGAIN; if (!ff_layout_init_mirror_ds(lseg->pls_layout, mirror)) goto noconnect; @@ -418,7 +418,7 @@ noconnect: ff_layout_send_layouterror(lseg); if (fail_return || !ff_layout_has_available_ds(lseg)) pnfs_error_mark_layout_for_return(ino, lseg); - ds = NULL; + ds = ERR_PTR(status); out: return ds; }