Hi Dan, On 2018/10/11 18:18, Dan Carpenter wrote: > On Thu, Oct 11, 2018 at 05:46:26PM +0800, Gao Xiang wrote: >> >> >> On 2018/10/11 16:44, Dan Carpenter wrote: >>> On Tue, Oct 09, 2018 at 10:07:13PM +0800, Gao Xiang wrote: >>>> This patch introduces inode hash function, test and set callbacks, >>>> and iget5_locked to find the right inode for 32-bit platforms. >>>> >>> >>> The way I read this changelog, we're trying to deal with corrupt file >>> systems? Is that correct? Presumably in the current code it could lead >>> to a Oops or something? >> >> No, this commit isn't trying to deal with corrupt file systems. >> In EROFS, the nid is not continuous and it represents the inode offset >> inode offset = nid * 32. >> Therefore the nid is 64-bit both for 32-bit and 64-bit platforms. However, >> i_ino is 'unsigned long', which means for 32-bit platforms, i_ino is not enough >> to contain the nid. >> >> Therefore, we should use iget5_locked for this case. > > I guess what I'm saying is, what are the user visible effects of this > patch? It's hard for me to tell from the patch description. Could you > please re-write the description and send a v2? Sorry for my just hurry reply. It seems I really misunderstood your point :-( If all nids are less than 32-bit, the user will see the correct inode/nid number for all 32-bit platforms, but if some nids are greater than 32-bit, it could be collisions without this patch for 32-bit platforms. This patch switch the inode number by XOR the high 32-bit and the low 32-bit, use customized tester to avoid collisions for 32-bit platforms. I will send v2 to fix the commit message...but it seems Greg is already merged in https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git/commit/?h=staging-testing&id=2abd7814138774eb56319e9dcc0abd08ece45424 Thanks, Gao Xiang > > regards, > dan carpenter > _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
