Messages in this thread | | | Date | Thu, 31 Jul 2014 13:11:42 +0300 | From | Boaz Harrosh <> | Subject | Re: [PATCH v8 04/22] Change direct_access calling convention |
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On 07/30/2014 10:45 PM, Matthew Wilcox wrote: <> >> + if (sector & (PAGE_SECTORS-1)) >> + return -EINVAL; > > Mmm. PAGE_SECTORS is private to brd (and also private to bcache!) at > this point. We've got a real mess of defines of SECTOR_SIZE, SECTORSIZE, > SECTOR_SHIFT and so on, dotted throughout various random include files. > I am not the river to flush those Augean stables today. > > I'll go with this, from the dcssblk driver: > > if (sector % (PAGE_SIZE / 512)) > return -EINVAL; >
Sigh, right, sure I did not mean to make that fight. Works as well
<> >> Style: Need a space between declaration and code (have you check-patch) > > That's a bullshit check. I don't know why it's in checkpatch. >
I did not invent the rules. But I do respect them. I think the merit of sticking to some common style is much higher then any particular style choice. Though this particular one I do like, because of the C rule that forces all declarations before code, so it makes it easier on the maintenance. In any way Maintainers are suppose to run checkpatch before submission, some do ;-)
<> >>> + if (size < 0) >> >> if(size < PAGE_SIZE), No? > > No, absolutely not. PAGE_SIZE is unsigned long, which (if I understand > my C integer promotions correctly) means that 'size' gets promoted to > an unsigned long, and we compare them unsigned, so errors will never be > caught by this check.
Good point I agree that you need a cast ie.
if(size < (long)PAGE_SIZE)
The reason I'm saying this is because of a bug I actually hit when playing with partitioning and fdisk, it came out that the last partition's size was not page aligned, and code that checked for (< 0) crashed because prd returned the last two sectors of the partition, since your API is sector based this can happen for you here, before you are memseting a PAGE_SIZE you need to test there is space, No?
> >
Thanks Boaz
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