|Summary:||nfs server RO, but client will not get error on write?|
|Product:||Red Hat Enterprise Linux 4||Reporter:||Rafal Wijata <wijata>|
|Component:||kernel||Assignee:||Ric Wheeler <rwheeler>|
|Status:||CLOSED WONTFIX||QA Contact:||Martin Jenner <mjenner>|
|Fixed In Version:||Doc Type:||Bug Fix|
|Doc Text:||Story Points:||---|
|Last Closed:||2010-03-16 18:32:10 UTC||Type:||---|
|oVirt Team:||---||RHEL 7.3 requirements from Atomic Host:|
Description Rafal Wijata 2007-12-21 08:25:50 UTC
Description of problem: I did this experiment, where one server exported filesystem via nfs(ro,sync,no_root_squash), and the second mounted it with mount -t nfs -o nfsvers=3 beta50:/mnt/mnt tmp resulted mount is server:/mnt/mnt /mnt/tmp nfs rw,v3,rsize=32768,wsize=32768,hard,tcp,lock,addr=server 0 0 Next, I wrote very simple client, which opens nfs file in O_APPEND|O_SYNC mode, and writes 1 byte in a infinite loop. While the client application runs I did following tests on server mount -o remount,ro /mnt/mnt the server filesystem remounted RO fine, the file written by client stopped growing, hence client haven't got any error to write() syscalls? It was writing forever. I verified it with strace as well. Next, instead of remounting it RO on the server, I changed the /etc/export line to RO mode and restarted nfs service. The result was similar, file stopped growing, the client stalled for a while, then again, it was not getting any errors to the write() syscalls. Is it bug, or nfs "mis" feature? Version-Release number of selected component (if applicable): kernel 2.6.9-42.0.10.ELsmp nfs-utils-1.0.6-70.EL4 Actual results: no write() error Expected results: error "RO filesystem" so client will not be lied, that the operation succeeded.
Comment 1 Peter Staubach 2008-06-18 15:44:09 UTC
Would you mind trying your "test" in a kernel newer than 2.6.9-56, please?
Comment 2 Rafal Wijata 2008-06-19 06:59:32 UTC
Well, this bug applies to RHEL4, and since I'm running RHEL4, i'd rather leave thay testing to someone who's actually running rhel5. BTW, there's a mistake in my first posting < I did this experiment, where one server exported filesystem via < nfs(ro,sync,no_root_squash), and the second mounted it with > I did this experiment, where one server exported filesystem via > nfs(rw,sync,no_root_squash), and the second mounted it with
Comment 3 Peter Staubach 2008-06-19 11:40:29 UTC
2.6.9-56 or newer kernels _are_ RHEL-4 kernels. RHEL-5 is based on 2.6.18. Please test using a RHEL-4 kernel at least as new as 2.6.9-56.
Comment 4 Rafal Wijata 2008-07-30 08:58:15 UTC
I really cannot. I was bound to rhel4.4/32bit, now I'm running rhel5.1/64bit
Comment 5 Peter Staubach 2008-07-30 12:15:48 UTC
Do you see this problem on your current system?
Comment 6 Rafal Wijata 2008-07-30 12:28:56 UTC
Haven't tested. It's not like I experienced some problems cause this bug - It just showed during tests. I suppose You guys should have two machines to perform the test on various environments.