On 08/15/17 17:20, Stefan Fritsch wrote:
> Hi,
>
> this is another try at making read clustering work for msdosfs.
>
> Last year, mpi@ implemented VFS read clustering for MSDOSFS in
>
> sys/msdosfs/denode.h 1.28
> sys/msdosfs/msdosfs_vnops.c 1.105
>
> This caused regressions when doing seeks past the end of the file and had.
> to be reverted. Then I tried to fix that in
>
> denode.h,v 1.31
> msdosfs_vnops.c,v 1.114
>
> But that caused different problems and had to be reverted, too. I have
> another test for that that I will commit soon.
>
> It seems that while netbsd uses DEV_BSIZE as base for the logical block
> numbers even in files, openbsd is more like freebsd and uses
> mnt_stat.f_iosize in that case. However, if the file system does accesses
> for metadata on the disk, it has to use DEV_BSIZE for accesses. So the
> fixes in 1.31/1.114 were wrong and the following diff is again based on
> 1.28/1.105 with some fixes in extendfile() to make seeks past the end of
> the file work.
>
>
> Testers/reviews/OKs welcome. Especially people who need msdosfs for
> booting via uefi. In any case, I won't commit until I get home again in a
> week.
>
> If my analysis with the block sizes is correct, I will add some
> clarifications to the bread/bwrite man page later.
Since I was the one who raised the second problem [0], I tried this
patch and everything seems to work fine. When I copy a binary file
on a msdos (uefi) partition (running the kernel with the patch) the
checksum remains the same:
# cp refind_x64.efi bootx64.efi
# ls -l refind_x64.efi bootx64.efi
-rw-r--r-- 1 root wheel 230856 Aug 15 19:49 bootx64.efi
-rw-r--r-- 1 root wheel 230856 Mar 9 11:09 refind_x64.efi
# sha256 refind_x64.efi bootx64.efi
SHA256 (refind_x64.efi) =
968596f40353ab8140867e71928fcd4c0bc2f39397aba8324f7255bcd57f0913
SHA256 (bootx64.efi) =
968596f40353ab8140867e71928fcd4c0bc2f39397aba8324f7255bcd57f0913
Kind regards,
Martijn Rijkeboer
[0] http://marc.info/?l=openbsd-tech&m=149725838018944&w=2
