Ben Hutchings: > Well, I don't understand how this is going wrong. All the logic in > fs/nfs/super.c (nfs_show_mount_options(), nfs_remount(), > nfs_parse_security_flavors(), nfs_compare_remount_data()) appears to do > the right thing with the sec option (stored in various structures as > auth_flavors[0] or au_flavor). > > Perhaps you could add some debug logging to work out how the option is > getting mangled on remount?
Unfortunately, I don't remember the detail of wheezy 3.2 kernel because I am reading various versions of mainline kernel. I am going to slightly mad and confused. I only remember that - At the first mount-time, NFS sets RPC_AUTH_UNIX (as default) without NFS_MOUNT_SECFLAVOUR. - nfs_show_mount_options() prints "sec=sys" since RPC_AUTH_UNIX is set, but still NFS_MOUNT_SECFLAVOUR is not set. - "mount -o remount" retrives "sec=sys" from /proc/mounts and passes it to mount(2). - nfs_remount() --> nfs_parse_mount_options() --> nfs_compare_remount_data() compares the flags and found that - "sec=sys" string is given. - but NFS_MOUNT_SECFLAVOUR flag is not set internally. and returns EINVAL. I guess one possible solution is stop printing "sec=" in nfs_show_mount_options() when NFS_MOUNT_SECFLAVOUR is not set. Another solution can be to force setting NFS_MOUNT_SECFLAVOUR when setting RPC_AUTH_UNIX as default. But in this case, we may need to care about /etc/mtab. In other words, - it may be hard to keep /etc/mtab and /proc/mounts equivalent. - some developers think + /etc/mtab and /proc/mounts are totally different things + it is unnecessary to make them equivalent. - finally symlinking /etc/mtab can cause a problem (like this case) since mount(8) and umount(8) highly depends upon /etc/mtab (or /proc/mounts). By the way, after forcing /etc/mtab as a regular file on my wheezy system, I found another problem of mount(8). I will report it to bugtrack later. J. R. Okajima -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/28099.1374649166@jrobl
