mkfs.f2fs: possible endianes bug in mkfs.f2fs roll-forward speed
I might found a bug in mkfs.f2fs. while experimenting with f2fs on my big
endian MIPS32 device (platform lantiq, 14.07-rc3, uclibc).
I ran into an issue that mkfs.f2fs, was not able to format block devices if I
did not specify the sector count manually.
I hunted it down to lib/libf2fs.c.
After I found that the detected sector count equals to the wanted sector count
shifted left (32+9) times.
I found two issues:
Firstly it uses ioctl BLKGETSIZE, which writes to an uint32_t the size of the
device.
As c->total_sectors is of type uint64_t, the value is written in to the first
4 bytes.
That explained the left shift of 32 bits.
Secondly BLKGETSIZE determines the size of the device in bytes (AFAIK, learned
by observation).
In the first branch of the if-block patched below, the c->total_sectors is
calculated by
c->total_sectors = stat_buf.st_size / c->sector_size;
The else branch omits the devision. sector_sice is mostly 512, that explained
the left shift by 9 bytes.
* fixes sector count calculation
* uses BLKGETSIZE64 if avail
Signed-off-by: joerg jungermann <jj@borkum.net>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
1 file changed