On Thu, Mar 3, 2016 at 8:03 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Thursday 03 March 2016 21:08:25 Deepa Dinamani wrote: >> On Thu, Mar 3, 2016 at 7:40 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: >> > On Wednesday 02 March 2016 23:50:01 Deepa Dinamani wrote: >> >> + /* >> >> + * Assign a default empty range [MAX_VFS_TIME, MIN_VFS_TIME]. >> >> + * This will help VFS detect filesystems that do not populate >> >> + * these fields in the superblock. >> >> + */ >> >> + s->s_time_min = MAX_VFS_TIME; >> >> + s->s_time_max = MIN_VFS_TIME; >> >> s->cleancache_poolid = CLEANCACHE_NO_POOL; >> > >> > I think this is still less clear than it should be, even with the >> > comment explaining it. >> > >> > As I just replied to Dave, how about initializing both to -1 instead? >> >> This was one of my first ideas. >> The reason I did not choose this is because >> 1. [-1, -1] is a valid range theoretically. >> 2. -1 would now be treated as a value. >> >> It is true that no filesystem is using -1 as a limit. >> But, I did not feel right excluding a perfectly good value. >> Choosing [1,1] or any other number except probably 0 would work the same way. >> >> This is the reason that I decided an invalid range should be >> represented by an invalid tuple and >> not a single value. >> My premise was that a range where min_time > max_time is invalid. > > Right. > >> My first choice here as in the first patch I shared with you privately >> was [1,-1]. >> But, the condition min_time < max_time can easily be achieved by >> changing just one of the values. >> For instance, [1, 2016]. But, this doesn't necessarily mean that the >> filesystem explicitly set both the values. > > I see where you are coming from here, but I think we could also assume > some minimum level of competence from the file system developers, so > I would not have quite described it this way ;-) Sorry, I did not mean to offend anybody. I was thinking it could avoid accidental update of only one of the bounds. The illustration I gave was meant to correlate with only setting s->s_time_max = U32_MAX (in 2106). - Deepa -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
