How is e2fsck's time_fudge supposed to behave?

So by default, we allow the superblock times to
be fudged by up to 24 hours.

I'm a little confused by e2fsck's time fudge current behavior, vs its apparent intent.

We do:

	if ( ... &&
            fs->super->s_mtime > (__u32) ctx->now) {
                pctx.num = fs->super->s_mtime;
                problem = PR_0_FUTURE_SB_LAST_MOUNT;
                if (fs->super->s_mtime <= (__u32) ctx->now + ctx->time_fudge)
                        problem = PR_0_FUTURE_SB_LAST_MOUNT_FUDGED;
                if (fix_problem(ctx, problem, &pctx)) {
                        fs->super->s_mtime = ctx->now;
                        fs->flags |= EXT2_FLAG_DIRTY;
                }

So if we are inside the time_fudge value we simply change the problem, but PR_0_FUTURE_SB_LAST_MOUNT_FUDGED behaves exactly like PR_0_FUTURE_SB_LAST_MOUNT, other than the message:

/* Last mount time is in the future (fudged) */
{ PR_0_FUTURE_SB_LAST_MOUNT_FUDGED,
N_("@S last mount time is in the future.\n\t(by less than a day, "
"probably due to the hardware clock being incorrectly set) "),
PROMPT_FIX, PR_PREEN_OK | PR_NO_OK },

vs:

        /* Last mount time is in the future */
        { PR_0_FUTURE_SB_LAST_MOUNT,
          N_("@S last mount time (%t,\n\tnow = %T) is in the future.\n"),
          PROMPT_FIX, PR_PREEN_OK | PR_NO_OK },

So unless I'm missing something, the whole fudge_time dance does nothing except change the message, and after reading lots of words in the e2fsck.conf manpage ;) this bit seems relevant as to the intent:

Quoted 2 lines

So by default, we allow the superblock times to
be fudged by up to 24 hours.

I had the impression that "allow" meant "ignore" but this still triggers exactly the same action and correction. Is that as intended?

I'll send a patch do a printf and take no other action if inside the fudge_time window, if that seems like the right thing to do.

On Fri 13-03-15 17:31:18, Eric Sandeen wrote:

Quoted 10 lines

So unless I'm missing something, the whole fudge_time dance does nothing except change the message, and after reading lots of words in the e2fsck.conf manpage ;) this bit seems relevant as to the intent:

Quoted 2 lines

So by default, we allow the superblock times to
be fudged by up to 24 hours.

I had the impression that "allow" meant "ignore" but this still triggers exactly the same action and correction. Is that as intended?

Quoted 2 lines

I'll send a patch do a printf and take no other action if inside the fudge_time window, if that seems like the right thing to do.

The actions became the same after commit
87aca2ad028b9 (e2fsck: fix last mount time and last write time in preen mode). Previously only fudged values were allowed to be fixed in the preen mode. The question is whether we now want to change e2fsck to just ignore difference within fudge or whether we just stop doing that fudge thing. Either makes sense to me...