Date: Wed, 1 Jun 2005 16:11:48 GMT From: BigB3 <bigbrother@bonbon.net> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/81770: Always "NFS append race" at every NFS mount with user specified read/write size Message-ID: <200506011611.j51GBmr0062727@www.freebsd.org> Resent-Message-ID: <200506011620.j51GK2RS099317@freefall.freebsd.org>
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>Number: 81770 >Category: kern >Synopsis: Always "NFS append race" at every NFS mount with user specified read/write size >Confidential: no >Severity: critical >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Wed Jun 01 16:20:01 GMT 2005 >Closed-Date: >Last-Modified: >Originator: BigB3 >Release: 4.11-Release >Organization: - >Environment: FreeBSD ikaros.XX.XXX.XX 4.11-RELEASE FreeBSD 4.11-RELEASE #8: Thu Mar 24 20:30:52 EET 2005 root@:/usr/obj/usr/src/sys/ikaros i386 and FreeBSD bigb3server.bbcluster.gr 4.11-RELEASE-p4 FreeBSD 4.11-RELEASE-p4 #6: Wed Apr 27 22:46:05 EEST 2005 root@ikaros.XXX.XXXXX.gr:/usr/obj/usr/src/sys/bigb3server i386 >Description: If you mount an NFS specifying either the read or write size (or both) and then you edit or create a file and save it, you always get an NFS error. The read and write size should be NOT a standard size. For example size of 13248 or 11840 or 8880 Thus, if you mount an NFS drive and tweak this option whatever file you edit, it is destroyed and in the syslog you get messages of "NFS append race @0:498" "NFS append race @0:3072" .. Note that the syslog messages are the same for the same read/write size. For example, if you mount the NFS drive with read/write 13248 in all the cases in all the files I got NFS append race 3200:3072 and 3200:169 or 3200:171 If I used the read/write size of 12000 I got NFS append race @2e00:4096 NFS append race @2e00:3072 for whatever file I edit on that machine. NOTE (1): We are talking for a single threaded application like cat(1) or vi(1). Thus, the same single threaded application makes an NFS append race on itself (I do not know how this is done) NOTE (2): _ALWAYS_ we get an NFS append race with we specify read/write size of a special value. NOTE (3): The text file should be more than some KBs...Dont edit a text file with 10 lines only NOTE (4): Some times (very often) even read/write size of 10*1024=10240 fails with NFS append race.. (This has been tested on a network with 7 computers) >How-To-Repeat: 1) Mount (tcp or udp) an NFS disk with size 13248 or 8880 or 11840 mount -o,-r=12000,-w=12000 alkystis:/users4 /mnt or mount -o,-r=13248,-w=13248 alkystis:/users4 /mnt 2) Edit a file or create a file which is some KB in size.. In my case I copy paste using the mouse a text file of 15KB.... vi /mnt/test.txt <paste the text here> (and save and exit (wq)) As soon as you save and exit you get 2 NFS Append race on your syslogd You can either do cat > /mnt/test << EOF <paste the text> EOF and you get 2 NFS append messages (the same range that was before). >Fix: The only temporar solution I think of is to use standard mount sizes of 8192 or 16384. >Release-Note: >Audit-Trail: >Unformatted:
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