Mercurial > illumos > git > illumos-joyent
changeset 25636:9dbc553a80a2
8040 NFSv4 client: 3-way deadlock between nfs4_bio(), nfs4_do_delegreturn(), and nfs4_flush_pages()
Reviewed by: Arne Jansen <arne@die-jansens.de>
Reviewed by: Vitaliy Gusev <gusev.vitaliy@icloud.com>
Approved by: Gordon Ross <gordon.w.ross@gmail.com>
| author | Marcel Telka <marcel@telka.sk> |
|---|---|
| date | Tue, 15 Dec 2020 22:08:36 +0100 |
| parents | f3c8f3a2a25c |
| children | ebef2b3dd433 |
| files | usr/src/uts/common/fs/nfs/nfs4_client.c usr/src/uts/common/fs/nfs/nfs4_vnops.c |
| diffstat | 2 files changed, 9 insertions(+), 33 deletions(-) [+] |
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--- a/usr/src/uts/common/fs/nfs/nfs4_client.c Thu Dec 31 10:47:42 2020 +0000 +++ b/usr/src/uts/common/fs/nfs/nfs4_client.c Tue Dec 15 22:08:36 2020 +0100 @@ -24,7 +24,7 @@ */ /* - * Copyright (c) 1983,1984,1985,1986,1987,1988,1989 AT&T. + * Copyright (c) 1983,1984,1985,1986,1987,1988,1989 AT&T. * All Rights Reserved */ @@ -464,33 +464,15 @@ rp = VTOR4(vp); mutex_enter(&rp->r_statelock); was_serial = (rp->r_serial == curthread); - if (rp->r_serial && !was_serial) { - klwp_t *lwp = ttolwp(curthread); - + if (rp->r_serial != NULL && !was_serial) { /* - * If we're the recovery thread, then purge current attrs - * and bail out to avoid potential deadlock between another - * thread caching attrs (r_serial thread), recov thread, - * and an async writer thread. + * Purge current attrs and bail out to avoid potential deadlock + * between another thread caching attrs (r_serial thread), this + * thread, and a thread trying to read or write pages. */ - if (recov) { - PURGE_ATTRCACHE4_LOCKED(rp); - mutex_exit(&rp->r_statelock); - return; - } - - if (lwp != NULL) - lwp->lwp_nostop++; - while (rp->r_serial != NULL) { - if (!cv_wait_sig(&rp->r_cv, &rp->r_statelock)) { - mutex_exit(&rp->r_statelock); - if (lwp != NULL) - lwp->lwp_nostop--; - return; - } - } - if (lwp != NULL) - lwp->lwp_nostop--; + PURGE_ATTRCACHE4_LOCKED(rp); + mutex_exit(&rp->r_statelock); + return; } /* @@ -3067,7 +3049,7 @@ nfs4_oo_hash_bucket_t *bucketp; nfs4_debug_msg_t *msgp; int i; - servinfo4_t *svp; + servinfo4_t *svp; /* * Code introduced here should be carefully evaluated to make
--- a/usr/src/uts/common/fs/nfs/nfs4_vnops.c Thu Dec 31 10:47:42 2020 +0000 +++ b/usr/src/uts/common/fs/nfs/nfs4_vnops.c Tue Dec 15 22:08:36 2020 +0100 @@ -2596,12 +2596,6 @@ osp->os_ref_count--; if (ep->error == 0) { - /* - * Avoid a deadlock with the r_serial thread waiting for - * os_sync_lock in nfs4_get_otw_cred_by_osp() which might be - * held by us. We will wait in nfs4_attr_cache() for the - * completion of the r_serial thread. - */ mutex_exit(&osp->os_sync_lock); *have_sync_lockp = 0;