On 4/18/20 11:40 AM, Eric Sandeen wrote: > On 4/18/20 11:04 AM, Eric Sandeen wrote: >> since access_time has no corresponding 10msIncrement field, my understanding was that it could only have a 2s granularity. > > Maybe your concern is whether the other _time fields should also be > truncated to 2s even though they have the _ms field? I don't think so; the > s_time_gran already limits in-core timestamp resolution to 10ms, which will > be properly translated when the inode is written to disk. > > atime has a different granularity though, so s_time_gran doens't help and we > must manually change it to 2s whenever we call something like current_time(), which > only enforces the 10ms granularity. > > So for cases like this: > > generic_fillattr(inode, stat); > + exfat_truncate_atime(&stat->atime); > > or this: > > inode->i_mtime = inode->i_atime = inode->i_ctime = > EXFAT_I(inode)->i_crtime = current_time(inode); > + exfat_truncate_atime(&inode->i_atime); > > I think it's clearly the right thing to do; anything finer than 2s will be thrown > away when the vfs inode atime is translated to the disk format, so we should never > hold finer granularity in the in-memory vfs inode. > > However, in exfat_get_entry_time() maybe all we need to do is set ts->tv_nsec to 0; > that might be clearer. so maybe this is better - diff --git a/fs/exfat/misc.c b/fs/exfat/misc.c index c8b33278d474..2c5629b4e7e6 100644 --- a/fs/exfat/misc.c +++ b/fs/exfat/misc.c @@ -89,7 +89,7 @@ void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts, ts->tv_sec += time_ms / 100; ts->tv_nsec = (time_ms % 100) * 10 * NSEC_PER_MSEC; } else - exfat_truncate_atime(ts); + ts->tv_nsec = 0; if (tz & EXFAT_TZ_VALID) /* Adjust timezone to UTC0. */ because the conversion should already limit tv_sec to a 2s granularity. -Eric
