>> as Herbert pointed out, the tagging is not recognized during >> the mounting. > >> I don't have ideas on the purpose, and google searching >> produced anything, anyway tonight, during users' sleep time, >> I will try again. > >> Also I would like to know if the failed tag option recognition >> is an issue which just comes with ext4, or is an issue related >> to linux-vserver and ext4. > > well, as the 'tag' option is Linux-VServer specific, it > naturally won't happen on a vanilla kernel (as there > simply is no such option in vanilla) > > but I don't think the issue is ext4 related (from the > kernel PoV), otherwise the testfs script would have > failed, as far as my guessing goes there are a bunch > of options: > > - the mount utility (for ext4) does mangle the options > somehow, and the 'tag' is not passed to the kernel > (most likely, would explain why ext3 works) > > - the scripts doing the mount clean up the arguments > (on accident or purpose) and thus remove the 'tag' > option before it can be passed to the kernel > > - the mount is done in several steps and/or involves > several remounts, which somehow 'lose' the tag on > the way ... > > not sure how to pinpoint this though, but if it cannot > be tracked down by analyzing the scripts/sources, we > could add some kernel debug messages to print the > mount/remount/unmount requests ... I'm doing some tests with the 'tag,notagcheck' options as kindly suggested by Daniel and Art. I observed that the '-o tag,notagcheck' is *always* recognised with ext4 if I put them at the beginning of the mount option For example: # mount -o tag,notagcheck,data=ordered,rw,usrjquota=aquota.user,grpjquota=aquota.group,jqfm t=vfsv0 /dev/sda3 /usr/local # cat /proc/mounts /dev/sda3 /usr/local ext4 rw,tag,notagcheck,relatime,user_xattr,barrier=1,data=ordered 0 0 The tag was recognized, but the usr/grp quota was lost :( And if try to put 'tag' at the end then it is *never* recognized # mount -o data=ordered,rw,usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv0,tag,notagcheck /dev/sda3 /usr/local/ root@sagredo:/etc# cat /proc/mounts /dev/sda3 /usr/local ext4 rw,notagcheck,relatime,user_xattr,barrier=1,data=ordered 0 0 And also in this case I lose the usr/grp quota support. I repeted the tests above many times, and I'm quite sure that this is a reproducible situation. I hope this could be of any help. Best regards Roberto Puzzanghera