From fe44fb23d6ccde4c914c44ef74ab8d9d9ba02bea Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 31 May 2022 11:03:06 -0400 Subject: pNFS: Don't keep retrying if the server replied NFS4ERR_LAYOUTUNAVAILABLE If the server tells us that a pNFS layout is not available for a specific file, then we should not keep pounding it with further layoutget requests. Fixes: 183d9e7b112a ("pnfs: rework LAYOUTGET retry handling") Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker --- fs/nfs/pnfs.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'fs/nfs/pnfs.c') diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index 68a87be3e6f9..4609e641710e 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -2152,6 +2152,12 @@ lookup_again: case -ERECALLCONFLICT: case -EAGAIN: break; + case -ENODATA: + /* The server returned NFS4ERR_LAYOUTUNAVAILABLE */ + pnfs_layout_set_fail_bit( + lo, pnfs_iomode_to_fail_bit(iomode)); + lseg = NULL; + goto out_put_layout_hdr; default: if (!nfs_error_is_fatal(PTR_ERR(lseg))) { pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode)); -- cgit v1.2.3-59-g8ed1b From 880265c77ac415090090d1fe72a188fee71cb458 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 31 May 2022 11:03:07 -0400 Subject: pNFS: Avoid a live lock condition in pnfs_update_layout() If we're about to send the first layoutget for an empty layout, we want to make sure that we drain out the existing pending layoutget calls first. The reason is that these layouts may have been already implicitly returned to the server by a recall to which the client gave a NFS4ERR_NOMATCHING_LAYOUT response. The problem is that wait_var_event_killable() could in principle see the plh_outstanding count go back to '1' when the first process to wake up starts sending a new layoutget. If it fails to get a layout, then this loop can continue ad infinitum... Fixes: 0b77f97a7e42 ("NFSv4/pnfs: Fix layoutget behaviour after invalidation") Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker --- fs/nfs/callback_proc.c | 1 + fs/nfs/pnfs.c | 15 +++++++++------ fs/nfs/pnfs.h | 1 + 3 files changed, 11 insertions(+), 6 deletions(-) (limited to 'fs/nfs/pnfs.c') diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c index c8520284dda7..c1eda73254e1 100644 --- a/fs/nfs/callback_proc.c +++ b/fs/nfs/callback_proc.c @@ -288,6 +288,7 @@ static u32 initiate_file_draining(struct nfs_client *clp, rv = NFS4_OK; break; case -ENOENT: + set_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags); /* Embrace your forgetfulness! */ rv = NFS4ERR_NOMATCHING_LAYOUT; diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index 4609e641710e..41a9b6b58fb9 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -469,6 +469,7 @@ pnfs_mark_layout_stateid_invalid(struct pnfs_layout_hdr *lo, pnfs_clear_lseg_state(lseg, lseg_list); pnfs_clear_layoutreturn_info(lo); pnfs_free_returned_lsegs(lo, lseg_list, &range, 0); + set_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags); if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags) && !test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) pnfs_clear_layoutreturn_waitbit(lo); @@ -1917,8 +1918,9 @@ static void nfs_layoutget_begin(struct pnfs_layout_hdr *lo) static void nfs_layoutget_end(struct pnfs_layout_hdr *lo) { - if (atomic_dec_and_test(&lo->plh_outstanding)) - wake_up_var(&lo->plh_outstanding); + if (atomic_dec_and_test(&lo->plh_outstanding) && + test_and_clear_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags)) + wake_up_bit(&lo->plh_flags, NFS_LAYOUT_DRAIN); } static bool pnfs_is_first_layoutget(struct pnfs_layout_hdr *lo) @@ -2025,11 +2027,11 @@ lookup_again: * If the layout segment list is empty, but there are outstanding * layoutget calls, then they might be subject to a layoutrecall. */ - if ((list_empty(&lo->plh_segs) || !pnfs_layout_is_valid(lo)) && + if (test_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags) && atomic_read(&lo->plh_outstanding) != 0) { spin_unlock(&ino->i_lock); - lseg = ERR_PTR(wait_var_event_killable(&lo->plh_outstanding, - !atomic_read(&lo->plh_outstanding))); + lseg = ERR_PTR(wait_on_bit(&lo->plh_flags, NFS_LAYOUT_DRAIN, + TASK_KILLABLE)); if (IS_ERR(lseg)) goto out_put_layout_hdr; pnfs_put_layout_hdr(lo); @@ -2413,7 +2415,8 @@ pnfs_layout_process(struct nfs4_layoutget *lgp) goto out_forget; } - if (!pnfs_layout_is_valid(lo) && !pnfs_is_first_layoutget(lo)) + if (test_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags) && + !pnfs_is_first_layoutget(lo)) goto out_forget; if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) { diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h index 07f11489e4e9..f331f067691b 100644 --- a/fs/nfs/pnfs.h +++ b/fs/nfs/pnfs.h @@ -105,6 +105,7 @@ enum { NFS_LAYOUT_FIRST_LAYOUTGET, /* Serialize first layoutget */ NFS_LAYOUT_INODE_FREEING, /* The inode is being freed */ NFS_LAYOUT_HASHED, /* The layout visible */ + NFS_LAYOUT_DRAIN, }; enum layoutdriver_policy_flags { -- cgit v1.2.3-59-g8ed1b