On 2018/4/3 4:03, Jaegeuk Kim wrote: > On 04/02, Chao Yu wrote: >> On 2018/3/30 23:39, Jaegeuk Kim wrote: >>> On 03/30, Junling Zheng wrote: >>>> On 2018/3/30 19:26, Chao Yu wrote: >>>>> On 2018/3/30 18:51, Junling Zheng wrote: >>>>>> Hi, >>>>>> >>>>>> On 2018/3/30 17:28, Chao Yu wrote: >>>>>>> Hi All, >>>>>>> >>>>>>> On 2018/3/28 1:19, Jaegeuk Kim wrote: >>>>>>>> From: katao <ka...@xiaomi.com> >>>>>>>> >>>>>>>> The args of wanted_total_sectors is calculated based >>>>>>>> on the DEFAULT_SECTOR_SIZE(512Bytes).get_device_info(i) >>>>>>>> may be reset dev_sector_size, we should reset the number >>>>>>>> of wanted_total_sectors. >>>>>>>> >>>>>>>> This bug was reported to Google Issue Tracker. >>>>>>>> Link: https://issuetracker.google.com/issues/76407663 >>>>>>> >>>>>>> I don't think this is the right way, since now we have changed previous >>>>>>> sector_counter's meaning, some applications, for example, like xfstests >>>>>>> will get >>>>>>> device's real sector size via blockdev --getsize64, then calculate >>>>>>> total wanted >>>>>>> sector count by total_wanted_size / real_sector_size, if we changed >>>>>>> default >>>>>>> sector size to 512bytes, xfstests will pass a wrong sector number, >>>>>>> result in >>>>>>> getting wrong partition size. >>>>>>> >>>>>>> For something worse, in order to get the correct sector number, we have >>>>>>> to >>>>>>> change the way of calculation method of xfstests for new mkfs, but how >>>>>>> can >>>>>>> xfstests know the current version of mkfs is new or old... >>>>>>> >>>>>>> I think the change didn't consider backward compatibility of mkfs, so, >>>>>>> in order >>>>>>> to keep that, we'd better to let user pass the right sector number >>>>>>> based on >>>>>>> their device, or we can introduce a new parameter to indicate user >>>>>>> wanted total >>>>>>> size. >>>>>>> >>>>>>> How do you think? >>>>>>> >>>>>> >>>>>> Agree. It's not backward-compatible. Most users can pass the correct >>>>>> sector number >>>>>> calculated by the real sector size. For those very few users using 512B >>>>>> despite of >>>>>> the actual sector size, all we need to do is informing them the real >>>>>> sector size. >>>>> >>>>> The problem is via passed sector number, we can't know user has already >>>>> knew the >>>>> real sector size or not, so we don't have any chance to info them. >>>>> >>>> >>>> Yeah, we can't guess users' behaviors. And only when wanted size is over >>>> device size, >>>> we can inform users the real sector size. >>> >>> So, current problem would be that wanted_total_sectors is given by: >>> - device sector size in xfstests >>> - 4KB in fs_mgr in Android >>> - 512B in recovery in Android >>> >>> And, my concern is why user always needs to think about sector_size to give >>> target image size, and I thought 512B would be good to set as a default >>> smallest >>> value. >> >> Of course, IMO, the most direct way is let user pass image size to mkfs.f2fs >> instead of caculated sector size, I think that will make all happy. > > No, it can become too large number. > >> >>> >>> Setting it 512B by default can give some confusion to users tho, it won't >>> hurt >>> the existing partitions or images. So, I bet users will get noticed quickly, >>> when formatting new partition under this rule. >> >> For those f2fs users, who makes image based on non-512B sector device, once >> they >> upgrade mkfs.f2fs, they will encounter this issue, that may make bad >> reputation. >> >> For interface in f2fs private ioctl, sysfs entry, or syscall, we keep the >> rule >> that once we want to do some change on it, we will not change the old >> interface >> directly, instead, introduce a new one to keep backward compatibility of old >> one. Still, I hope we can keep that rule in mkfs.f2fs parameter. > > Okay, so in order to give more flexible ways, it'd be fine to add > wanted_sector_size by "-w" so that we could blow out all the existing concern > like this.
That's better. > > From: katao <ka...@xiaomi.com> > Date: Tue, 27 Mar 2018 13:25:46 +0800 > Subject: [PATCH] libf2fs,mkfs.f2fs: add wanted_sector_size for > wanted_total_sectors > > The wanted_total_sectors was determined by device sector size, but sometimes > we don't know precise sector_size by default. So, let's give > wanted_sector_size > in such the ambiguous situation. > > Signed-off-by: katao <ka...@xiaomi.com> > Signed-off-by: Junling Zheng <zhengjunl...@huawei.com> > Signed-off-by: Jaegeuk Kim <jaeg...@google.com> Reviewed-by: Chao Yu <yuch...@huawei.com> Thanks, ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
