From: Miklos Szeredi Subject: nfs: lock stuck after interrupt Date: Thu, 17 Apr 2008 19:44:08 +0200 Message-ID: Cc: trond.myklebust@fys.uio.no, eshel@almaden.ibm.com, neilb@suse.de, akpm@linux-foundation.org, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org To: bfields@fieldses.org Return-path: Sender: linux-kernel-owner@vger.kernel.org List-ID: 1) on server lock file X 2) on client lock file X blocks 3) on client send interrupt to process doing locking locking syscall restarted, continues blocking 4) on server release lock on file X on client lock is acquired 5) on client release lock on file X 6) on client lock file X blocks Everything up to the last step is fine, but something goes wrong during the final unlock. Stopping the nfs-server removes the stray lock. Here's a trace on the server: lockd: request from 192.168.1.1, port=862 lockd: LOCK called lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk) lockd: get host tucsk lockd: nsm_monitor(tucsk) lockd: nlm_lookup_file (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000) lockd: creating file for (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000) lockd: found file 0ad074c0 (count 0) lockd: nlmsvc_lock(ubda/96317, ty=1, pi=1, 0-99, bl=1) lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk) lockd: get host tucsk lockd: nlmsvc_lookup_block f=0ad074c0 pd=1 0-99 ty=1 lockd: get host tucsk lockd: created block 0aeabf80... lockd: vfs_lock_file returned 1 lockd: nlmsvc_insert_block(0aeabf80, -1) lockd: release host tucsk lockd: nlmsvc_lock returned 50331648 lockd: LOCK status 3 lockd: release host tucsk lockd: nlm_release_file(0ad074c0, ct = 2) lockd: request from 192.168.1.1, port=862 lockd: CANCEL called lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk) lockd: get host tucsk lockd: nlm_lookup_file (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000) lockd: found file 0ad074c0 (count 1) lockd: nlmsvc_cancel(ubda/96317, pi=1, 0-99) lockd: nlmsvc_lookup_block f=0ad074c0 pd=1 0-99 ty=1 lockd: check f=0ad074c0 pd=1 0-99 ty=1 cookie=36120000 lockd: unlinking block 0aeabf80... lockd: freeing block 0aeabf80... lockd: release host tucsk lockd: nlm_release_file(0ad074c0, ct = 2) lockd: CANCEL status 0 lockd: release host tucsk lockd: nlm_release_file(0ad074c0, ct = 1) lockd: closing file ubda/96317 lockd: request from 192.168.1.1, port=862 lockd: LOCK called lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk) lockd: get host tucsk lockd: nsm_monitor(tucsk) lockd: nlm_lookup_file (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000) lockd: creating file for (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000) lockd: found file 0ad074c0 (count 0) lockd: nlmsvc_lock(ubda/96317, ty=1, pi=2, 0-99, bl=1) lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk) lockd: get host tucsk lockd: nlmsvc_lookup_block f=0ad074c0 pd=2 0-99 ty=1 lockd: get host tucsk lockd: created block 0aeab240... lockd: vfs_lock_file returned 0 lockd: freeing block 0aeab240... lockd: release host tucsk lockd: nlm_release_file(0ad074c0, ct = 2) lockd: release host tucsk lockd: nlmsvc_lock returned 0 lockd: LOCK status 0 lockd: release host tucsk lockd: nlm_release_file(0ad074c0, ct = 1) lockd: request from 192.168.1.1, port=862 lockd: UNLOCK called lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk) lockd: get host tucsk lockd: nlm_lookup_file (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000) lockd: found file 0ad074c0 (count 0) lockd: nlmsvc_unlock(ubda/96317, pi=3, 0-9223372036854775807) lockd: nlmsvc_cancel(ubda/96317, pi=3, 0-9223372036854775807) lockd: nlmsvc_lookup_block f=0ad074c0 pd=3 0-9223372036854775807 ty=2 lockd: UNLOCK status 0 lockd: release host tucsk lockd: nlm_release_file(0ad074c0, ct = 1) Everything looks normal, yet... This is 100% reproducable for me (ext3 exported over nfs, server and client: 2.6-git). Miklos