I've got a bug report about a possible regression from one of our QA people. They were testing some of the recent write_inode/COMMIT changes with this script: ----------------[snip]----------------- #! /usr/bin/env bash servers="server:/export" nfsstat -c -3 for SRV in $servers do mount $SRV /media -o nfsvers=3 rm -f /media/tmp.file time dd if=/dev/zero bs=1024k count=2000 of=/media/tmp.file umount /media nfsstat -c -3 done ----------------[snip]----------------- The changes have definitely reduced the number of commit calls, but frequently we see these errors pop and the filesystem isn't unmounted. umount.nfs: /media: device is busy umount.nfs: /media: device is busy ...if I call /bin/sync just before the umount, then it works fine. I added a cat /proc/meminfo just before the umount and see this: MemTotal: 980376 kB MemFree: 12364 kB Buffers: 3804 kB Cached: 803584 kB SwapCached: 0 kB Active: 172376 kB Inactive: 650252 kB Active(anon): 5592 kB Inactive(anon): 9808 kB Active(file): 166784 kB Inactive(file): 640444 kB Unevictable: 0 kB Mlocked: 0 kB SwapTotal: 2064376 kB SwapFree: 2064376 kB Dirty: 0 kB Writeback: 0 kB AnonPages: 15240 kB Mapped: 9008 kB Shmem: 160 kB Slab: 123572 kB SReclaimable: 28096 kB SUnreclaim: 95476 kB KernelStack: 1016 kB PageTables: 2428 kB NFS_Unstable: 90384 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 2554564 kB Committed_AS: 80836 kB VmallocTotal: 34359738367 kB VmallocUsed: 41980 kB VmallocChunk: 34359685244 kB HardwareCorrupted: 0 kB AnonHugePages: 0 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB DirectMap4k: 8128 kB DirectMap2M: 1040384 kB ...note that Dirty and Writeback are 0, but NFS_Unstable is still at 90M or so. So, I think the problem is likely that the unstable pages are preventing the umount. I've not done much investigation beyond this yet, but figured I'd toss the bug report out here in case anyone has thoughts on the cause and how it should be fixed. I can reproduce this fairly easily on my virtualized test rig in case anyone has patches that they want me to test. -- Jeff Layton <jlayton@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
