C quotactl and ZFS

[nxg]

Greetings

[I'm not positive whether I should post this here or in the 'storage' forum]

I'm trying to get programmatic access to ZFS quotas, and I'm not finding my questions answered by what seem to be the relevant manpages -- specifically quotactl(2) on 14.0.

Puzzle 1 is that the manpage states bluntly that ‘Currently quotas are supported only for the "ufs" file system.’ But (a) bug 234413 from 2019/12.0, states that ‘ZFS implements quotactl(2) as of r336017; the man page needs to be updated.’ Also (b) quotactl does seem to work. Question: does this work only by accident? (ie, it's going to stop working unexpectedly!) Is there a manpage I'm missing? Should I just open up a docbug report?

The program below works, in the sense that it produces numbers which are right if the block-size is 512kB. But I can find nothing, neither in quotactl() nor in ufs/ufs/quota.h, which tells me that unequivocally, and in a way which I'm confident will work on a pool with a different ashift value.

...
#include <ufs/ufs/quota.h>

int main(int argc, char** argv)
{
    struct dqblk quota_info;
    int status = quotactl("/home/me",
                          QCMD(Q_GETQUOTA, USRQUOTA),
                          -1,
                          &quota_info);

    if (status != 0) {
        perror(argv[0]);
        exit(1);
    }

    printf("hard=%ld soft=%ld, used=%ld\n",
           quota_info.dqb_bhardlimit,
           quota_info.dqb_bsoftlimit,
           quota_info.dqb_curblocks);
}

 

[Cath O'Deray]

open up a docbug report?

Probably. I see nothing ZFS-related in recent history for the page.

 

[nxg]

Thanks for the reassurance!

I've added bug 279249.

I'll maybe ask on the storage forum.